| **Debt - Narrative (Details)**                                                                                   | 3 Months Ended                                                               | 12 Months Ended                               | 3 Months Ended                                        | 12 Months Ended                                       |                                                        |                                                                                                                                     |                                                                                                                                                 |                                                                                                                                                            |                                                                                                                                                                                                                                                   | 1 Months Ended                                                                                                                                                                                                                                           |                                                                                                                                                                     |                                                                                                                                                                   |                                                                                                                                                                              |                                                                                                                                                                              |                                                                                                                                                                                                   |                                                                                                                                                                           | 1 Months Ended                                                                                                                                                            |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                       | 12 Months Ended                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                        |                                                                                                                                                              | 12 Months Ended                                                                                                                                               | 3 Months Ended                                                                                                                                                                                     |                                                                                                                                                                                             |                                                                                                                                                                     | 1 Months Ended                                                                                                                                                        | 3 Months Ended                                                                                                                                                                                        | 12 Months Ended                                                                                                                                                                                                                                 | 1 Months Ended                                                                                                                                                                                                                                                       | 3 Months Ended                                                                                                                                                                                         | 12 Months Ended                                                                                                                                                                                    |                                                                                                                                                                                          | 1 Months Ended | 3 Months Ended                                                                                                                                                                                                                    |                                                                                                                                                                                                                                   | 3 Months Ended                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                                              | 12 Months Ended                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                                     | 1 Months Ended                                                                                                                                                                                                                                                                                                                     | 11 Months Ended                                                                                                                                                                                                                                                            | 1 Months Ended                                                                                                                                                                                                            | 12 Months Ended                                                                                                                                                                  |                                                                                                                                                                                  |                                                                                                                                                                                 |                                                                                                                                                                                 | 12 Months Ended |                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                                       |         |                                                                                                                                                                                          | 3 Months Ended                                                                                                                                                   | 6 Months Ended                                                                                                                                                                           | 12 Months Ended                                                                                                                                                              | 0 Months Ended                                                                                                                                                                                                                                                                   | 3 Months Ended                                                                                                                                                                                                                                                              | 12 Months Ended                                                                                                                                                                                                                                                 | 3 Months Ended                                                                                                                                                              | 12 Months Ended                                                                                                                                                             | 3 Months Ended                                                                                                                                                                                              | 12 Months Ended                                                                                                                   |                                                                                                                                           | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                          | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                            | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                          | 1 Months Ended                                                                                                                                                                                                                                                                   | 12 Months Ended                                                                                                                                                                                                                                                                  | 1 Months Ended                                                                                                                                                                                                                                                                           | 3 Months Ended                                                                                                                                                                                                                                                                             | 1 Months Ended                                                                                                                                                                                                                                                                                                    | 12 Months Ended                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                      | 1 Months Ended                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                      | 1 Months Ended                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                       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                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------|-----------------------------------------------|-------------------------------------------------------|-------------------------------------------------------|--------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------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||
| **Debt Instrument [Line Items]**                                                                                 |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                       |                                                                                                   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                                                                                                                                                               |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Payments to subsidiary to meet convenant requirement                                                             |                                                                         |                                          | $ 0nav_PaymentsToSubsidiaryToMeetConvenantRequirement | $ 0nav_PaymentsToSubsidiaryToMeetConvenantRequirement | $ 0nav_PaymentsToSubsidiaryToMeetConvenantRequirement  |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                      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| Debt Instrument, Covenant Compliance, Fixed Charge Coverage Ratio, Maximum                                       |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                               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                                                                                                                                                               |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                          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         |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | 125.00%nav_DebtInstrumentCovenantComplianceFixedChargeCoverageRatioMaximum/ dei_LegalEntityAxis= nav_NavistarFinancialCorporationMember |   |   |   |   |   |   |   |   |   |
| Line of Credit Facility, Maximum Borrowing Capacity                                                              |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         | 840,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_DebtInstrumentAxis= nav_BankFacilityMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  | 1,000,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        | 175,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= nav_AssetBasedCreditFacilityMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                       |     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                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   | 40,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_CreditFacilityAxis= us-gaap_LetterOfCreditMember/ us-gaap_RangeAxis= us-gaap_MaximumMember | 100,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_CreditFacilityAxis= us-gaap_RevolvingCreditFacilityMember/ us-gaap_DebtInstrumentAxis= nav_BankFacilityMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 500,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_CreditFacilityAxis= us-gaap_RevolvingCreditFacilityMember/ us-gaap_DebtInstrumentAxis= nav_BankFacilityMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 340,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_CreditFacilityAxis= nav_TermLoanMember/ us-gaap_DebtInstrumentAxis= nav_BankFacilityMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Loans Payable to Bank                                                                                            |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  | 372,000,000us-gaap_LoansPayableToBank/ us-gaap_LongtermDebtTypeAxis= us-gaap_AssetBackedSecuritiesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                       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                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                                                |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   | 502,000,000us-gaap_LoansPayableToBank/ dei_LegalEntityAxis= nav_NavistarFinancialRetailReceivablesCorporationMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_AssetBackedSecuritiesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 200,000,000us-gaap_LoansPayableToBank/ us-gaap_CreditFacilityAxis= us-gaap_RevolvingCreditFacilityMember/ us-gaap_DebtInstrumentAxis= nav_BankFacilityMember/ dei_LegalEntityAxis= nav_MexicanFinanceSubsidiaryMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Periodic Payment, Principal                                                                     |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                               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                                                                                                  |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |          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                                             |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                               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         |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | 9,000,000us-gaap_DebtInstrumentPeriodicPaymentPrincipal/ us-gaap_CreditFacilityAxis= nav_TermLoanMember/ us-gaap_DebtInstrumentAxis= nav_BankFacilityMember/ nav_InstallmentPaymentsBySetAxis= nav_InstallmentPaymentsSetTwoMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |   |   |   |   |   |   |   |   |
| Line of Credit Facility, Participation Fee Reduction, Amount Outstanding in Excess of Maximum Borrowing Capacity |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |          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                                             |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                               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                                                                                                                                                               |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   | 50,000,000nav_LineofCreditFacilityParticipationFeeReductionAmountOutstandinginExcessofMaximumBorrowingCapacity/ us-gaap_CreditFacilityAxis= us-gaap_LetterOfCreditMember |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Long-term Line of Credit                                                                                         |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                | 1,000,000,000us-gaap_LineOfCredit/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                  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                                                 |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Periodic Payment, Principal, Percentage                                                         |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  | 0.25%nav_DebtInstrumentPeriodicPaymentPrincipalPercentage/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember         |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                    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                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                             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| Debt Instrument, Interest Rate, Stated Percentage                                                                |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                               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                                                                                                                        |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          | 3.00%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember    |                                                                                                                                                                                                                                                                              | 4.50%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                       | 4.50%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                       | 4.50%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 4.75%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember        | 4.75%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                       |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    | 6.50%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_LongtermDebtTypeAxis= nav_TaxExemptBondMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                             | 6.50%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_LongtermDebtTypeAxis= nav_TaxExemptBondMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                   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                                                                                                                 |                                                                                                                                                                                                                                                                                                   | 2.80%us-gaap_DebtInstrumentInterestRateStatedPercentage/ nav_InterestRateAxis= us-gaap_InterestRateFloorMember/ us-gaap_LongtermDebtTypeAxis= nav_FinancedLeaseObligationsMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 7.60%us-gaap_DebtInstrumentInterestRateStatedPercentage/ nav_InterestRateAxis= us-gaap_InterestRateCapMember/ us-gaap_LongtermDebtTypeAxis= nav_FinancedLeaseObligationsMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Repayments of Long-term Debt                                                                                     |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   | 404,000,000us-gaap_RepaymentsOfLongTermDebt/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        | 300,000,000us-gaap_RepaymentsOfLongTermDebt/ nav_SeniorSecuredTermLoanCreditFacilityLevel1Axis= nav_ManufacturingOperationsMember |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                             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| Payments of Debt Extinguishment Costs                                                                            |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                                                                                  |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |          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                                             |                                                                                                                              | 13,000,000us-gaap_PaymentsOfDebtExtinguishmentCosts/ nav_SeniorSecuredTermLoanCreditFacilityLevel1Axis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                               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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Face Amount                                                                                     |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                | 200,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember                                         | 500,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_VfnFacilityMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 750,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_VfnFacilityMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      | 250,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_InvestorNotesMaturingTwoThousandandFifteenMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 250,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_InvestorNotesMaturingTwoThousandandFifteenMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 200,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_InvestorNotesMaturingOctoberTwoThousandThirteenMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 224,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_InvestorNotesMaturingOctoberTwoThousandThirteenMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  | 74,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_InvestorNotesMaturingTwoThousandandEighteenMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 1,000,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_InvestorNotesMaturingTwoThousandandEighteenMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 | 0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                           |                                                                                                                                                                                               | 1,000,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              | 570,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                          |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              | 200,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                   | 200,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                   |                                                                                                                                                                                                                                                                                                  | 411,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                    |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            | 40,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_PromissoryNoteMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember      |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     | 225,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= nav_TaxExemptBondMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                             | 135,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_IllinoisFinanceAuthorityRecoveryZoneFacilityRevenueBondMember/ us-gaap_LongtermDebtTypeAxis= nav_TaxExemptBondMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 90,000,000us-gaap_DebtInstrumentFaceAmount/ us-gaap_DebtInstrumentAxis= nav_CountyOfCookRecoveryZoneFacilityRevenueBondsMember/ us-gaap_LongtermDebtTypeAxis= nav_TaxExemptBondMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                               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                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Proceeds from Issuance of Debt                                                                                   |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    | 60,000,000us-gaap_ProceedsFromIssuanceOfDebt/ us-gaap_DebtInstrumentAxis= nav_InvestorNotesMaturingTwoThousandandEighteenMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 800,000,000us-gaap_ProceedsFromIssuanceOfDebt/ us-gaap_DebtInstrumentAxis= nav_InvestorNotesMaturingTwoThousandandEighteenMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                            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                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                             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                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Proceeds from Issuance of Senior Long-term Debt                                                                  |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 | 310,000,000us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                  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                                                 |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  | 402,000,000us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember    |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                 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                                 |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                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                    |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Related Commitment Fees and Debt Issuance Costs                                                             |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  | 9,000,000us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                             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            |                                                                                                                                                                                                                                                                                                                                                                                              | 8,000,000us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts/ us-gaap_BalanceSheetLocationAxis= us-gaap_OtherNoncurrentAssetsMember/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 1,000,000us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts/ us-gaap_BalanceSheetLocationAxis= us-gaap_AdditionalPaidInCapitalMember/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Unamortized Premium                                                                             |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 | 4,000,000us-gaap_DebtInstrumentUnamortizedPremium/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember           |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                  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                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                                                                                                                    |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Accrued Interest Received                                                                                        |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 | 10,000,000nav_AccruedInterestReceived/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                       |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                  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                                                 |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                                                                                                                    |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Interest Rate, Effective Percentage                                                             |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 | 8.50%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember  |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                  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                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Redemption Price, Percentage                                                                    |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                               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                                                                                                                   |           | 100.00%us-gaap_DebtInstrumentRedemptionPricePercentage/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                         |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         | 100.00%us-gaap_DebtInstrumentRedemptionPricePercentage/ us-gaap_DebtInstrumentRedemptionPeriodAxis= nav_DebtInstrumentRedemptionPeriodSixMember/ us-gaap_LongtermDebtTypeAxis= nav_TaxExemptBondMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      | 104.125%us-gaap_DebtInstrumentRedemptionPricePercentage/ us-gaap_DebtInstrumentRedemptionPeriodAxis= us-gaap_DebtInstrumentRedemptionPeriodTwoMember/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioOneMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 102.75%us-gaap_DebtInstrumentRedemptionPricePercentage/ us-gaap_DebtInstrumentRedemptionPeriodAxis= us-gaap_DebtInstrumentRedemptionPeriodThreeMember/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioOneMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 101.375%us-gaap_DebtInstrumentRedemptionPricePercentage/ us-gaap_DebtInstrumentRedemptionPeriodAxis= us-gaap_DebtInstrumentRedemptionPeriodFourMember/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioOneMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 100.00%us-gaap_DebtInstrumentRedemptionPricePercentage/ us-gaap_DebtInstrumentRedemptionPeriodAxis= us-gaap_DebtInstrumentRedemptionPeriodFiveMember/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioOneMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                     | 103.00%us-gaap_DebtInstrumentRedemptionPricePercentage/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioTwoMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 100.00%us-gaap_DebtInstrumentRedemptionPricePercentage/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioThreeMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                      |                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                           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| Proceeds from Issuance of Long-term Debt                                                                         |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                           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                       |    | 2,300,000us-gaap_ProceedsFromIssuanceOfLongTermDebt/ us-gaap_LongtermDebtTypeAxis= nav_TaxExemptBondMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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                                                  |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                                                |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Redemption Price, Principal Amount Redeemed                                                     |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                               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                                                                                                                                                               |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          | 50,000,000nav_DebtInstrumentRedemptionPricePrincipalAmountRedeemed/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioTwoMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_RangeAxis= us-gaap_MaximumMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Redemption Period                                                                               |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |          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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Early Repayment of Senior Debt                                                                                   |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                               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us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 50,000,000us-gaap_EarlyRepaymentOfSeniorDebt/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioTwoMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                     | 100,000,000us-gaap_EarlyRepaymentOfSeniorDebt/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioTwoMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember          |                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                                                                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                                                                                                                                        |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                             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                                                                                                                                                                                            |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Gains (Losses) on Extinguishment of Debt                                                                         |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                               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                                                                         |                                                                                                                                                                                                                                                                             | (8,000,000)us-gaap_GainsLossesOnExtinguishmentOfDebt/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioTwoMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                        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                                                                                                |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                     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                                                                                                                                                    |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Redemption, Premium, Percentage of Principal Amount Redeemed                                    |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                               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                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                       | 1.00%nav_DebtInstrumentRedemptionPremiumPercentageOfPrincipalAmountRedeemed/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioThreeMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                        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                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                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                                   |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Basis Spread on Variable Rate                                                                   |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                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                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               | 350.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  | 450.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember/ us-gaap_VariableRateAxis= us-gaap_EurodollarMember | 125.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember/ us-gaap_VariableRateAxis= us-gaap_LondonInterbankOfferedRateLIBORMember |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                        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                                                           |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   | 2.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_DebtInstrumentAxis= nav_PromissoryNoteMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember/ us-gaap_VariableRateAxis= us-gaap_LondonInterbankOfferedRateLIBORMember |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                        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                                                                                                                                                                                                                                  | 50.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ nav_DebtInstrumentRedemptionScenarioAxis= nav_DebtInstrumentRedemptionScenarioThreeMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember/ us-gaap_VariableRateAxis= nav_TreasuryRateMember | 325.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_DebtInstrumentAxis= nav_AmendedandRestatedAssetBasedCreditFacilityMember/ us-gaap_RangeAxis= us-gaap_MaximumMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember/ us-gaap_VariableRateAxis= us-gaap_LondonInterbankOfferedRateLIBORMember | 225.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_DebtInstrumentAxis= nav_AmendedandRestatedAssetBasedCreditFacilityMember/ us-gaap_RangeAxis= us-gaap_MaximumMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember/ us-gaap_VariableRateAxis= us-gaap_BaseRateMember |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             | 275.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_DebtInstrumentAxis= nav_AmendedandRestatedAssetBasedCreditFacilityMember/ us-gaap_RangeAxis= us-gaap_MinimumMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember/ us-gaap_VariableRateAxis= us-gaap_LondonInterbankOfferedRateLIBORMember | 175.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_DebtInstrumentAxis= nav_AmendedandRestatedAssetBasedCreditFacilityMember/ us-gaap_RangeAxis= us-gaap_MinimumMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember/ us-gaap_VariableRateAxis= us-gaap_BaseRateMember |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                    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                                                                               |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Payments for Derivative Instrument, Investing Activities                                                         |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |          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                                             |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                               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                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                       |                                                                                                   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                                                                                                                                                               |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                  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                                                                                                                                                                                                       |                                                                                                                                                                                                                                 | 125,000,000us-gaap_PaymentsForDerivativeInstrumentInvestingActivities/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_OptionIndexedToIssuersEquityEquityAxis= us-gaap_CallOptionMember |                                                                                                                                                                                                                                                                                 | 125,000,000us-gaap_PaymentsForDerivativeInstrumentInvestingActivities/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_OptionIndexedToIssuersEquityEquityAxis= us-gaap_CallOptionMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                           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| Option Indexed to Issuer's Equity, Indexed Shares                                                                |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |          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                                                                                                                                                               |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                  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                                                                                                                                                                                                       | 11,337,870us-gaap_OptionIndexedToIssuersEquityIndexedShares/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_OptionIndexedToIssuersEquityEquityAxis= us-gaap_CallOptionMember |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 | 11,337,870us-gaap_OptionIndexedToIssuersEquityIndexedShares/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_OptionIndexedToIssuersEquityEquityAxis= us-gaap_CallOptionMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember           |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                           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| Class of Warrant or Right, Exercise Price of Warrants or Rights                                                  |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              | $ 60.14us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                                                                                                                    |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                             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                                                                                                                                                    |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Warrants and Rights Outstanding                                                                                  |                                                                         |                                          | 4,814,551us-gaap_WarrantsAndRightsOutstanding         |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                       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                                                                                                                              |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                       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                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                                                                                                                                                            |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Option Indexed to Issuer's Equity, Strike Price                                                                  |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            | $ 54.07us-gaap_OptionIndexedToIssuersEquityStrikePrice1/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember  |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                       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                                                                                                                              |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                       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                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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                                                  |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                                                |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    | $ 58.40us-gaap_OptionIndexedToIssuersEquityStrikePrice1/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_OptionIndexedToIssuersEquityEquityAxis= us-gaap_CallOptionMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | $ 50.27us-gaap_OptionIndexedToIssuersEquityStrikePrice1/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_OptionIndexedToIssuersEquityEquityAxis= us-gaap_CallOptionMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember               |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                                                                                                         | $ 50.27us-gaap_OptionIndexedToIssuersEquityStrikePrice1/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Proceeds from Issuance of Warrants                                                                               |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                | 87,000,000us-gaap_ProceedsFromIssuanceOfWarrants/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                       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                                                                                                                              |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                          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                                                                                                                        |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              | 87,000,000us-gaap_ProceedsFromIssuanceOfWarrants/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                     |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                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                    |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Charge Related to Repurchase of Debt                                                                             |                                                                         | 11,000,000nav_ChargeRelatedtoRepurchaseofDebt |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                  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                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                      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                            |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Shares of Call Options Unwound                                                                                   |                                                                         | 8,026,456nav_SharesofCallOptionsUnwound       |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                           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                                                                                                                              |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                  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                                                                                                       |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Shares of Warrants Unwound                                                                                       |                                                                         | 6,523,319nav_SharesofWarrantsUnwound          |                                                  |                                                  |                                                   | 6,523,319nav_SharesofWarrantsUnwound/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                      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                             |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                               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           |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                  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                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                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                                                                                                      |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                               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| Proceeds from Convertible Debt                                                                                   |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                               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                                                                                                                   |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            | 196,000,000us-gaap_ProceedsFromConvertibleDebt/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                      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                            |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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                                                                                                                                                                    |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                             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                                                                                                                                                    |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Payments of Debt Issuance Costs                                                                                  |                                                                         |                                          | 15,000,000us-gaap_PaymentsOfDebtIssuanceCosts         | 20,000,000us-gaap_PaymentsOfDebtIssuanceCosts         | 57,000,000us-gaap_PaymentsOfDebtIssuanceCosts          |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                 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                                  |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                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                                                                                                                                  |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                        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                                                           | 3,000,000us-gaap_PaymentsOfDebtIssuanceCosts/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                  |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                       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                                           |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                       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                                                                                                                                                                                                                           |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                      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| Issuance Costs                                                                                                   |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                               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                                                                                                                   |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            | 1,000,000nav_IssuanceCosts/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                                    |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                      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                            |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Long-term Debt, Fair Value                                                                                       |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       | 177,000,000us-gaap_LongTermDebtFairValue/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember                                      | 367,000,000us-gaap_LongTermDebtFairValue/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember                                      |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                   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                                       |                                                                                                                                                          | 58,000,000us-gaap_LongTermDebtFairValue/ us-gaap_DebtInstrumentAxis= nav_PromissoryNoteWithLessorInCherokeeAlabamaMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              | 177,000,000us-gaap_LongTermDebtFairValue/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                      | 177,000,000us-gaap_LongTermDebtFairValue/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                      |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                | 367,000,000us-gaap_LongTermDebtFairValue/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                      |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                               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                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                         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| Debt Instrument, Convertible, Carrying Amount of Equity Component                                                |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       | 22,000,000us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember | 44,000,000us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                             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                                                                                                                                                        |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              | 22,000,000us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 22,000,000us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                | 44,000,000us-gaap_DebtInstrumentConvertibleCarryingAmountOfTheEquityComponent/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                           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| Debt Issuance Cost                                                                                               |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 | (4,000,000)us-gaap_DebtIssuanceCosts/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableToBanksMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                        |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              | 3,000,000us-gaap_DebtIssuanceCosts/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                            |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                              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                                                                                                          |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                       |                                                                  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| Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger                                        |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                               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                                                                                                                   |           | 130.00%us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 130.00%us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                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| Debt Instrument, Convertible, Threshold Trading Days                                                             |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                                                                                  |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |          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                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            | 20us-gaap_DebtInstrumentConvertibleThresholdTradingDays/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_RangeAxis= us-gaap_MinimumMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 20us-gaap_DebtInstrumentConvertibleThresholdTradingDays/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_RangeAxis= us-gaap_MinimumMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                                                                            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                                                       |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Convertible, Threshold Consecutive Trading Days                                                 |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           | 30 days                                                                                                                                                                                                                           | 30 days                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                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| Debt Instrument, Convertible, Measurement Period, Trading Days, Ending                                           |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           | 10nav_DebtInstrumentConvertibleMeasurementPeriodTradingDaysEnding/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                       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                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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| Debt Instrument, Convertible, Measurement Period, Business Days                                                  |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     | 10             | 5                                                                                                                                                                                                                                 | 5                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                             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                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                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| Debt Instrument Convertible Conversion Price Percent                                                             |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                               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                                                                                                                   |           | 100.00%nav_DebtInstrumentConvertibleConversionPricePercent/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                     | 100.00%nav_DebtInstrumentConvertibleConversionPricePercent/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                     |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          | 100.00%nav_DebtInstrumentConvertibleConversionPricePercent/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                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                                                                                                                 |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                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                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                           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                        |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument Convertible Conversion Ratio Basis                                                               |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                               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                                                                                                                   |           |                                                                                                                                                                                                                              | 1,000nav_DebtInstrumentConvertibleConversionRatioBasis/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                         |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                       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                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                                                                                                    |                                                                                                                                                                                                                                                                                                 | 1,000nav_DebtInstrumentConvertibleConversionRatioBasis/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember  | 1,000nav_DebtInstrumentConvertibleConversionRatioBasis/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember   | 1,000nav_DebtInstrumentConvertibleConversionRatioBasis/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Threshold percentage of last reported sale price of common stock                                                 |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |          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                                                                                                                                                               | 98.00%nav_ThresholdPercentageOfLastReportedSalePriceOfCommonStock/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_RangeAxis= us-gaap_MaximumMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 98.00%nav_ThresholdPercentageOfLastReportedSalePriceOfCommonStock/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_RangeAxis= us-gaap_MaximumMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                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| Debt Instrument, Convertible, Conversion Ratio                                                                   |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            | 18.4946us-gaap_DebtInstrumentConvertibleConversionRatio1/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                       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                                                                                                                              |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                          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                                                                                                                        |           |                                                                                                                                                                                                                              | 17.1233us-gaap_DebtInstrumentConvertibleConversionRatio1/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                       |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                  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                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                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                                                                                                                                                          |                                                                                                                                                                                                                                                                                                 | 19.891us-gaap_DebtInstrumentConvertibleConversionRatio1/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember | 17.1233us-gaap_DebtInstrumentConvertibleConversionRatio1/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum                                            |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                            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                                                                                                       |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                      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| Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum                                            |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                               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                                                                                                                   |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                       | 7.70%us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMaximum/ us-gaap_LongtermDebtTypeAxis= nav_DebtOfMajorityOwnedDealershipsMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                      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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Present Value of Future Minimum Lease Payments, Sale Leaseback Transactions                                      |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   | 6,000,000us-gaap_PresentValueOfFutureMinimumLeasePaymentsSaleLeasebackTransactions/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 24,000,000us-gaap_PresentValueOfFutureMinimumLeasePaymentsSaleLeasebackTransactions/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                 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                                                                                  |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                         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| Capital Lease Obligations                                                                                        |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   | 4,000,000us-gaap_CapitalLeaseObligations/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                           | 2,000,000us-gaap_CapitalLeaseObligations/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                            |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                             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                                                                                                            |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                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| Long-term Debt                                                                                                   |                                                                         |                                          | 5,224,000,000us-gaap_LongTermDebt                     |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     | 2,266,000,000us-gaap_LongTermDebt/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember                                                     |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              | 1,242,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 1,018,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   | 2,958,000,000us-gaap_LongTermDebt/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                                  |                                                                                                                                                          | 40,000,000us-gaap_LongTermDebt/ us-gaap_DebtInstrumentAxis= nav_PromissoryNoteWithLessorInCherokeeAlabamaMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember          | 694,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                         | 693,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= us-gaap_LineOfCreditMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                          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                                                                                                                                                                                                           | 0us-gaap_LongTermDebt/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                      | 544,000,000us-gaap_LongTermDebt/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 177,000,000us-gaap_LongTermDebt/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                               | 177,000,000us-gaap_LongTermDebt/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                               | 181,000,000us-gaap_LongTermDebt/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                         |                                                                                                                                                                                                                                                                                                                | 371,000,000us-gaap_LongTermDebt/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                                               | 0us-gaap_LongTermDebt/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_ConvertibleSubordinatedDebtMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                      | 30,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= nav_DebtOfMajorityOwnedDealershipsMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 48,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= nav_DebtOfMajorityOwnedDealershipsMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 29,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 39,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    | 225,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= nav_TaxExemptBondMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember                         | 225,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= nav_TaxExemptBondMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            | 184,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= nav_FinancedLeaseObligationsMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 218,000,000us-gaap_LongTermDebt/ us-gaap_LongtermDebtTypeAxis= nav_FinancedLeaseObligationsMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                        |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                              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                                                                                                                                                          |                                                                                                                                                                                                                                                                                                   |   |   | 181,000,000us-gaap_LongTermDebt/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_GEOperatingAgreementMember/ us-gaap_LongtermDebtTypeAxis= nav_FinancedLeaseObligationsMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember | 167,000,000us-gaap_LongTermDebt/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_GEOperatingAgreementMember/ us-gaap_LongtermDebtTypeAxis= nav_FinancedLeaseObligationsMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |   |   |   |   |   |   |   |   |   |   |   |   | 535,000,000us-gaap_LongTermDebt/ nav_CurrencyDenominationAxis= nav_UnitedStatesDollarsAndMexicanPesosMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 489,000,000us-gaap_LongTermDebt/ nav_CurrencyDenominationAxis= nav_UnitedStatesDollarsAndMexicanPesosMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |   |   |   |   |   |   |
| Debt instrument, percentage of borrowings denominated in countries currency                                      |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                           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64.00%nav_DebtInstrumentPercentageOfBorrowingsDenominatedInCountriesCurrency/ nav_CurrencyDenominationAxis= currency_MXN/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |
| Debt Instrument, Term                                                                                            |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                 | 2 years |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                            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                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                              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| Debt Instrument, Number Of Installment Payments                                                                  |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            | 16nav_DebtInstrumentNumberOfInstallmentPayments/ us-gaap_DebtInstrumentAxis= nav_PromissoryNoteMember/ us-gaap_LongtermDebtTypeAxis= us-gaap_NotesPayableOtherPayablesMember/ us-gaap_StatementBusinessSegmentsAxis= nav_ManufacturingOperationsMember |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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                                                  |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                              |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                       |                                                                                              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                                                                                                                                                                    |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | 8nav_DebtInstrumentNumberOfInstallmentPayments/ us-gaap_CreditFacilityAxis= nav_TermLoanMember/ us-gaap_DebtInstrumentAxis= nav_BankFacilityMember/ nav_InstallmentPaymentsBySetAxis= nav_InstallmentPaymentsSetTwoMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |   |   |   |   |   |   |   |   |
| Cash Dividends Paid to Parent Company by Consolidated Subsidiaries                                               | 30,000,000us-gaap_CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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                                                  |                                                                                                                              |                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                                                                          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                                                                                                                                                                    |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                 |                                     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Pledged Assets, Other, Not Separately Reported on Statement of Financial Position                                |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     | 1,200,000,000us-gaap_PledgedAssetsNotSeparatelyReportedOnStatementOfFinancialPosition/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 989,000,000us-gaap_PledgedAssetsNotSeparatelyReportedOnStatementOfFinancialPosition/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |                                                                                                                                                                         |                                                                                                                                                                         |                                                                                                                                                                                              |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                  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           |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                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| Line Of Credit Facility Term Length                                                                              |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         | 5                                                                                                                                                                                                 |                                                                                                                                                                      |                                                                                                                                                                      |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                   |                                                                                                                                                         |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                  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                                                                                                                                                                                                                                                                                     |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |     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              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Commercial Paper                                                                                                 |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                            |                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                                                                                                       |                                                                                                                                                                                                                      |                                                                                                                                                                             |                                                                                                                                                                             |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                           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                                                                                                                                               |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | 74,000,000us-gaap_CommercialPaper/ nav_CurrencyDenominationAxis= currency_USD |   |   | 1,000,000,000us-gaap_CommercialPaper/ nav_CurrencyDenominationAxis= currency_MXN |   |   |
| Proceeds from issuance of securitized debt                                                                       |                                                                         |                                          | 255,000,000us-gaap_ProceedsFromIssuanceOfSecuredDebt  | 529,000,000us-gaap_ProceedsFromIssuanceOfSecuredDebt  | 1,313,000,000us-gaap_ProceedsFromIssuanceOfSecuredDebt |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                 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                |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                             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                                                                                                                 |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                         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                                                                                                                                                                                                                      |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                           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| Secured Debt                                                                                                     |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                               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                                                                                                                   |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                       |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                            |                                                                                                                                                                        |                                                                                                                                                                        |                                                                                                                                                           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         |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   | 36,000,000us-gaap_SecuredDebt/ dei_LegalEntityAxis= nav_InternationalTruckLeasingCorporationMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | 49,000,000us-gaap_SecuredDebt/ dei_LegalEntityAxis= nav_InternationalTruckLeasingCorporationMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |   |   |   |   |   |   |   |   |   |   |
| Loans Pledged as Collateral                                                                                      |                                                                         |                                          |                                                  |                                                  |                                                   |                                                                                                                                |                                                                                                                                            |                                                                                                                                                       |                                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                     |                                                                                                                                                                |                                                                                                                                                              |                                                                                                                                                                         |                                                                                                                                                                         |                                                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                   |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                 |                                                                                                                                                         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 |                                                                                                                                                          |                                                                                                                                                                                               |                                                                                                                                                                                        |                                                                                                                                                                |                                                                                                                                                                  |                                                                                                                                                                                                  |                                                                                                                                                                                                                                            |                                                                                                                                                                                                                                                                 |                                                                                                                                                                                                   |                                                                                                                                                                                               |                                                                                                                                                                                     |           |                                                                                                                                                                                                                              |                                                                                                                                                                                                                              |                                                                                                                                                                                                                                                                                                                   |                                                                                                                       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                                                                                                  |                                                                                                                                                                            |                                                                                                                                                                            |            |                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                  |    |                                                                                                                                                                                     |                                                                                                                                                             |                                                                                                                                                                                     |                                                                                                                                                                         |                                                                                                                                                                                                                                                                             |          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                                                                                                                                                               |                                                                                                                                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                                  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                                                                                                                                                                                                       |                                                                                                                                                                                                                                 |                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                          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         |                                                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   | $ 48,000,000us-gaap_LoansPledgedAsCollateral/ dei_LegalEntityAxis= nav_InternationalTruckLeasingCorporationMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember | $ 61,000,000us-gaap_LoansPledgedAsCollateral/ dei_LegalEntityAxis= nav_InternationalTruckLeasingCorporationMember/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember |   |   |   |   |   |   |   |   |   |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Accrued interest received from the issuance of debt. The amount received is calculated from the beginning of the prior coupon period under the terms of the debt to the date of issuance.
+ References
No definition available.
+ Details**Name:**nav_AccruedInterestReceived**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Charge Related to Repurchase of Debt
+ References
No definition available.
+ Details**Name:**nav_ChargeRelatedtoRepurchaseofDebt**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument Convertible Conversion Price Percent
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentConvertibleConversionPricePercent**Namespace Prefix:**nav_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The basis for applying ratio applied to the debt for purposes of determining the number of shares of the equity security into which the debt will be converted.
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentConvertibleConversionRatioBasis**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument, Convertible, Measurement Period, Business Days
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentConvertibleMeasurementPeriodBusinessDays**Namespace Prefix:**nav_**Data Type:**us-types:durationStringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument, Convertible, Measurement Period, Trading Days, Ending
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentConvertibleMeasurementPeriodTradingDaysEnding**Namespace Prefix:**nav_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument, Covenant Compliance, Fixed Charge Coverage Ratio, Maximum
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentCovenantComplianceFixedChargeCoverageRatioMaximum**Namespace Prefix:**nav_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument, Number Of Installment Payments
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentNumberOfInstallmentPayments**Namespace Prefix:**nav_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt instrument, borrowings denominated in pesos percentage
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentPercentageOfBorrowingsDenominatedInCountriesCurrency**Namespace Prefix:**nav_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument, Periodic Payment, Principal, Percentage
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentPeriodicPaymentPrincipalPercentage**Namespace Prefix:**nav_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument, Redemption Period
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentRedemptionPeriod**Namespace Prefix:**nav_**Data Type:**xbrli:durationItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument, Redemption, Premium, Percentage of Principal Amount Redeemed
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentRedemptionPremiumPercentageOfPrincipalAmountRedeemed**Namespace Prefix:**nav_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument, Redemption Price, Principal Amount Redeemed
+ References
No definition available.
+ Details**Name:**nav_DebtInstrumentRedemptionPricePrincipalAmountRedeemed**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Issuance Costs
+ References
No definition available.
+ Details**Name:**nav_IssuanceCosts**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line of Credit Facility, Participation Fee Reduction, Amount Outstanding in Excess of Maximum Borrowing Capacity
+ References
No definition available.
+ Details**Name:**nav_LineofCreditFacilityParticipationFeeReductionAmountOutstandinginExcessofMaximumBorrowingCapacity**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line Of Credit Facility Term Length
+ References
No definition available.
+ Details**Name:**nav_LineOfCreditFacilityTermLength**Namespace Prefix:**nav_**Data Type:**us-types:dateStringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Payments to subsidiary to meet convenant requirement
+ References
No definition available.
+ Details**Name:**nav_PaymentsToSubsidiaryToMeetConvenantRequirement**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Shares of Call Options Unwound
+ References
No definition available.
+ Details**Name:**nav_SharesofCallOptionsUnwound**Namespace Prefix:**nav_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Shares of Warrants Unwound
+ References
No definition available.
+ Details**Name:**nav_SharesofWarrantsUnwound**Namespace Prefix:**nav_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Threshold percentage of last reported sale price of common stock
+ References
No definition available.
+ Details**Name:**nav_ThresholdPercentageOfLastReportedSalePriceOfCommonStock**Namespace Prefix:**nav_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 7Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6455398&loc=d3e45280-112737
+ Details**Name:**us-gaap_CapitalLeaseObligations**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 235 -Section S99 -Paragraph 2 -Subparagraph (SX 210.9-06) -URI http://asc.fasb.org/extlink&oid=6882215&loc=d3e537971-122884Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 06 -Article 9Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph b -Article 12Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(b)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690
+ Details**Name:**us-gaap_CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Exercise price per share or per unit of warrants or rights outstanding.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690
+ Details**Name:**us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1**Namespace Prefix:**us-gaap_**Data Type:**num:perShareItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 7Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(a)(3)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.13(2)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a(3) -Article 5Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 2 -Article 9
+ Details**Name:**us-gaap_CommercialPaper**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage points added to the reference rate to compute the variable rate on the debt instrument.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instruments must exceed threshold percentage for a specified number of trading days to trigger conversion feature, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Face (par) amount of debt instrument at time of issuance.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Contractual interest rate for funds borrowed, under the debt agreement.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum contractual interest rate for funds borrowed, under the debt agreement.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Minimum contractual interest rate for funds borrowed, under the debt agreement.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of the required periodic payments applied to principal.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
+ References
No definition available.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of debt premium that was originally recognized at the issuance of the instrument that has yet to be amortized.
+ References
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| X                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of debt issuance costs (for example, but not limited to, legal, accounting, broker, and regulatory fees).
+ References
No definition available.
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the charge against earnings during the period for commitment fees and debt issuance expenses.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow for the extinguishment of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Including the current and noncurrent portions, carrying value as of the balance sheet date of loans from a bank with maturities initially due after one year or beyond the normal operating cycle if longer.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16(a)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 7Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20, 22 -Article 5Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.
+ References
No definition available.
+ Details**Name:**us-gaap_LongTermDebtFairValue**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of issuer's shares to which the option contract is indexed.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Exercise or strike price stated in the contract for options indexed to the issuer's equity shares.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(1) -URI http://asc.fasb.org/extlink&oid=6940734&loc=d3e22047-110879Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 50 -Paragraph 5 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=6445032&loc=d3e90205-114008
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| X                                                                                                                                                                                                                                                                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow for derivative instruments during the period, which are classified as investing activities, excluding those designated as hedging instruments.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow for incremental, external costs directly pertaining to an early extinguishment of debt, including legal costs and prepayment penalties, and excluding interest and repayment of debt principal.
+ References
No definition available.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.
+ References
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The carrying amount, as of the date of the latest financial statement presented, of all assets that are pledged as collateral for the payment of the related debt obligation primarily arising from secured borrowings, repurchase agreements or other current or potential obligations, where the secured party does not have the right by contract or custom to sell or re-pledge the collateral and therefore are not reclassified and separately reported in the statement of financial position.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Present value of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow from the issuance of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder.
+ References
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| - Definition
The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.
+ References
No definition available.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow from amounts received from issuance of long-term debt that is wholly or partially secured by collateral. Excludes proceeds from tax exempt secured debt.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow from a borrowing with the highest claim on the assets of the entity in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle, if longer).
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow from issuance of rights to purchase common shares at predetermined price (usually issued together with corporate debt).
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.
+ References
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