| **Allowance for Doubtful Accounts (Details) (USD $)In Millions, unless otherwise specified**                                                                                                                                                                                                                       | 3 Months Ended | 12 Months Ended |     |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|-----------------|-----|
||
| Financing Receivable By Class Number of Portfolio Segments                                                                                                                                                                                                                                                         |           | 2               |     |   |  |   |  |   |
| Loss on Contract Termination for Default                                                                                                                                                                                                                                                                           |           | $ 6             |     | $ 20 |  | $ 22 |  |   |
| Financing Receivable, Allowance for Credit Losses                                                                                                                                                                                                                                                                  |           | 50              |     | 96 |  | 104 |  | 51 |
| Provision for Loan, Lease, and Other Losses                                                                                                                                                                                                                                                                        |           | 14              |     | (6) |  | 29 |  |   |
| Financing Receivable, Allowance for Credit Losses, Write-downs                                                                                                                                                                                                                                                     |           | (13)            | [1] | (40) | [1] | (37) | [1] |   |
| Retail Portfolio [Member]                                                                                                                                                                                                                                                                                          |           |            |     |   |  |   |  |   |
| Financing Receivable Number Of Classes Of Receivables In Each Portfolio                                                                                                                                                                                                                                            | 1              |            |     |   |  |   |  |   |
| Financing Receivable, Allowance for Credit Losses                                                                                                                                                                                                                                                                  |           | 31              |     | 58 |  | 58 |  | 27 |
| Provision for Loan, Lease, and Other Losses                                                                                                                                                                                                                                                                        |           | 3               |     | (5) |  | 26 |  |   |
| Financing Receivable, Allowance for Credit Losses, Write-downs                                                                                                                                                                                                                                                     |           | (7)             | [1] | (22) | [1] | (26) | [1] |   |
| Wholesale Portfolio [Member]                                                                                                                                                                                                                                                                                       |           |            |     |   |  |   |  |   |
| Financing Receivable Number Of Classes Of Receivables In Each Portfolio                                                                                                                                                                                                                                            |           | 1               |     |   |  |   |  |   |
| Financing Receivable, Allowance for Credit Losses                                                                                                                                                                                                                                                                  |           | 2               |     | 2 |  | 1 |  | 0 |
| Provision for Loan, Lease, and Other Losses                                                                                                                                                                                                                                                                        |           | (2)             |     | 0 |  | 1 |  |   |
| Financing Receivable, Allowance for Credit Losses, Write-downs                                                                                                                                                                                                                                                     |           | 0               | [1] | 0 | [1] | 0 |  |   |
| Trade and Other Receivables [Member]                                                                                                                                                                                                                                                                               |           |            |     |   |  |   |  |   |
| Financing Receivable, Allowance for Credit Losses                                                                                                                                                                                                                                                                  |           | 17              |     | 36 |  | 45 |  | 24 |
| Provision for Loan, Lease, and Other Losses                                                                                                                                                                                                                                                                        |           | 13              |     | (1) |  | 2 |  |   |
| Financing Receivable, Allowance for Credit Losses, Write-downs                                                                                                                                                                                                                                                     |           | $ (6)           | [1] | $ (18) | [1] | $ (11) | [1] |   |
|                                                                                                                                                                                                                                                                                                                    |
| [1]We repossess sold and leased vehicles on defaulted finance receivables and leases, and place them into Inventories. Losses recognized at the time of repossession and charged against the allowance for doubtful accounts were $6 million , $20 million, and $22 million in 2012, 2011, and 2010. respectively. |

| X                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Financing Receivable By Class Number of Portfolio Segments
+ References
No definition available.
+ Details**Name:**nav_FinancingReceivableByClassNumberOfPortfolioSegments**Namespace Prefix:**nav_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Financing Receivable Number Of Classes Of Receivables In Each Portfolio
+ References
No definition available.
+ Details**Name:**nav_FinancingReceivableNumberOfClassesOfReceivablesInEachPortfolio**Namespace Prefix:**nav_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
A valuation allowance for financing receivables that are expected to be uncollectible.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953423-111524
+ Details**Name:**us-gaap_FinancingReceivableAllowanceForCreditLosses**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of direct write-downs of financing receivables charged against the allowance.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953423-111524
+ Details**Name:**us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of the loss on termination of a contract for default.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 912 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6539154&loc=d3e52595-109384
+ Details**Name:**us-gaap_LossOnContractTerminationForDefault**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The sum of the periodic provision charged to earnings, based on an assessment of uncollectibility from the counterparty on account of loan, lease or other credit losses, to reduce these accounts to the amount that approximates their net realizable value.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 11 -Article 9Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953423-111524Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-DEP -Paragraph 168, 169, 170 -IssueDate 2006-05-01 -Chapter 5 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.11) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882
+ Details**Name:**us-gaap_ProvisionForLoanLeaseAndOtherLosses**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |