| **Summary of Significant Accounting Policies - Product Warranty Liability (Details) (USD $)In Millions, except Per Share data, unless otherwise specified**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | 3 Months Ended                                                                                                                                                                                | 12 Months Ended                                                                                                                                                                                               | 3 Months Ended                                                                                                                                                                                              |
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| **Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   |   |  |   |  |   |  |   |   |   |   |   |   |
| Balance at beginning of period                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   | $ 1,118us-gaap_ProductWarrantyAccrual |   | $ 1,349us-gaap_ProductWarrantyAccrual |  | $ 1,118us-gaap_ProductWarrantyAccrual |  | $ 598us-gaap_ProductWarrantyAccrual |  |   | $ 1,349us-gaap_ProductWarrantyAccrual |   |   |   | $ 598us-gaap_ProductWarrantyAccrual |
| Costs accrued and revenues deferred                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   | 302us-gaap_ProductWarrantyAccrualWarrantiesIssued |  | 469us-gaap_ProductWarrantyAccrualWarrantiesIssued |  | 575us-gaap_ProductWarrantyAccrualWarrantiesIssued |  |   |   |   |   |   |   |
| Product Warranty Accrual, Divestures                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   | 0nav_ProductWarrantyAccrualDivestures |  | (3)nav_ProductWarrantyAccrualDivestures |  | 0nav_ProductWarrantyAccrualDivestures |  |   |   |   |   |   |   |
| Currency translation adjustment                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   | (4)us-gaap_ProductWarrantyAccrualCurrencyTranslationIncreaseDecrease |  | (2)us-gaap_ProductWarrantyAccrualCurrencyTranslationIncreaseDecrease |  | (4)us-gaap_ProductWarrantyAccrualCurrencyTranslationIncreaseDecrease |  |   |   |   |   |   |   |
| Adjustments to pre-existing warranties(A)(B)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | (10)us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease                                                                                                                                 | (29)us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease                                                                                                                                                 | 152us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease                                                                                                                                                |   |   | 10us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease | 55us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease | [1],[2] | 404us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease | [1],[2] | 404us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease | [1],[2] |   |   |   |   |   |   |
| Payments and revenues recognized                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   | (505)us-gaap_ProductWarrantyAccrualPayments |  | (637)us-gaap_ProductWarrantyAccrualPayments |  | (455)us-gaap_ProductWarrantyAccrualPayments |  |   |   |   |   |   |   |
| Balance at end of period                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 1,197us-gaap_ProductWarrantyAccrual                                                                                                                                                           |                                                                                                                                                                                                          | 1,349us-gaap_ProductWarrantyAccrual                                                                                                                                                                         |   |   |   | 1,197us-gaap_ProductWarrantyAccrual |  | 1,349us-gaap_ProductWarrantyAccrual |  | 1,118us-gaap_ProductWarrantyAccrual |  |   |   |   | 1,118us-gaap_ProductWarrantyAccrual |   |   |
| Less: Current portion                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | 535us-gaap_ProductWarrantyAccrualClassifiedCurrent                                                                                                                                            |                                                                                                                                                                                                          | 601us-gaap_ProductWarrantyAccrualClassifiedCurrent                                                                                                                                                          |   |   |   | 535us-gaap_ProductWarrantyAccrualClassifiedCurrent |  | 601us-gaap_ProductWarrantyAccrualClassifiedCurrent |  | 551us-gaap_ProductWarrantyAccrualClassifiedCurrent |  |   |   |   | 551us-gaap_ProductWarrantyAccrualClassifiedCurrent |   |   |
| Noncurrent accrued product warranty and deferred warranty revenue                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 662us-gaap_ProductWarrantyAccrualNoncurrent                                                                                                                                                   |                                                                                                                                                                                                          | 748us-gaap_ProductWarrantyAccrualNoncurrent                                                                                                                                                                 |   |   |   | 662us-gaap_ProductWarrantyAccrualNoncurrent |  | 748us-gaap_ProductWarrantyAccrualNoncurrent |  | 567us-gaap_ProductWarrantyAccrualNoncurrent |  |   |   |   | 567us-gaap_ProductWarrantyAccrualNoncurrent |   |   |
| Warranty Recoveries                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        | 13nav_WarrantyRecoveries | 27nav_WarrantyRecoveries |   |   |  |   |  |   |  |   |   |   |   |   |   |
| Extended Warranty Programs [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   |   |  |   |  |   |  |   |   |   |   |   |   |
| **Extended Warranty Program:**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   |   |  |   |  |   |  |   |   |   |   |   |   |
| Deferred Revenue, Revenue Recognized                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   | 132us-gaap_DeferredRevenueRevenueRecognized/ us-gaap_DeferredRevenueArrangementTypeAxis= nav_ExtendedWarrantyProgramsMember |  | 87us-gaap_DeferredRevenueRevenueRecognized/ us-gaap_DeferredRevenueArrangementTypeAxis= nav_ExtendedWarrantyProgramsMember |  | 63us-gaap_DeferredRevenueRevenueRecognized/ us-gaap_DeferredRevenueArrangementTypeAxis= nav_ExtendedWarrantyProgramsMember |  |   |   |   |   |   |   |
| Deferred Revenue                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 437us-gaap_DeferredRevenue/ us-gaap_DeferredRevenueArrangementTypeAxis= nav_ExtendedWarrantyProgramsMember                                                                                    |                                                                                                                                                                                                          | 420us-gaap_DeferredRevenue/ us-gaap_DeferredRevenueArrangementTypeAxis= nav_ExtendedWarrantyProgramsMember                                                                                                  |   |   |   | 437us-gaap_DeferredRevenue/ us-gaap_DeferredRevenueArrangementTypeAxis= nav_ExtendedWarrantyProgramsMember |  | 420us-gaap_DeferredRevenue/ us-gaap_DeferredRevenueArrangementTypeAxis= nav_ExtendedWarrantyProgramsMember |  | 364us-gaap_DeferredRevenue/ us-gaap_DeferredRevenueArrangementTypeAxis= nav_ExtendedWarrantyProgramsMember |  |   |   |   | 364us-gaap_DeferredRevenue/ us-gaap_DeferredRevenueArrangementTypeAxis= nav_ExtendedWarrantyProgramsMember |   |   |
| recoverable [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   |   |  |   |  |   |  |   |   |   |   |   |   |
| **Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   |   |  |   |  |   |  |   |   |   |   |   |   |
| Adjustments to pre-existing warranties(A)(B)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   | 13us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ nav_SpecificAccrualAxis= nav_RecoverableMember |   |   |  |   |  |   |  |   |   |   |   |   |   |
| Product Warranty Accrual [Member]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   |   |  |   |  |   |  |   |   |   |   |   |   |
| **Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |                                                                                                                                                                                          |                                                                                                                                                                                                          |                                                                                                                                                                                                        |   |   |   |   |  |   |  |   |  |   |   |   |   |   |   |
| Adjustments to pre-existing warranties(A)(B)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | $ 25us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 30us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember                 |                                                                                                                                                                                                        | $ 164us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 40us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember |   |   |  |   |  |   |  | $ 42us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 52us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 48us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 149us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 104us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 123us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember |
| Product Warranty Accrual, Preexisting Increase Decrease Per Share, Net of Tax                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                          | $ (0.36)nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 1.89nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 2.04nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 0.50nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember |   |   |  |   |  |   |  | $ 0.52nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 0.64nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 0.60nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 2.16nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 1.51nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember | $ 1.76nav_ProductWarrantyAccrualPreexistingIncreaseDecreasePerShareNetOfTax/ us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis= nav_ProductWarrantyAccrualMember |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| [1](B)In the first quarter of 2013, we recognized $13 million of charges for adjustments to pre-existing warranties for a specific warranty issue related to component parts from a supplier. Also during the first quarter of 2013, we reached an agreement for reimbursement from this supplier for this amount and other costs previously accrued. As a result of this agreement, we recognized a recovery of $27 million within Costs of products sold and recorded a receivable within Other current assets. In the second quarter of 2013, we recognized a warranty recovery of $13 million within Income (loss) from discontinued operations, net of tax and recorded a receivable within Other current assets.In the third quarter of 2012, we recognized $10 million of adjustments to pre-existing warranties for a specific warranty issue related to component parts from a supplier. Also during the quarter, we reached agreement for reimbursement from such supplier and recognized a recovery for that amount and recorded a receivable within Other current assets.[2](A)Adjustments to pre-existing warranties reflect changes in our estimate of warranty costs for products sold in prior periods. Such adjustments typically occur when claims experience deviates from historic and expected trends. Our warranty liability is generally affected by component failure rates, repair costs, and the timing of failures. Future events and circumstances related to these factors could materially change our estimates and require adjustments to our liability. In addition, new product launches require a greater use of judgment in developing estimates until historical experience becomes available. In the first quarter of 2014, we recorded adjustments for changes in estimates of $52 million or $0.64 per diluted share. In the second quarter of 2014, we recorded adjustments for changes in estimates of $42 million, or $0.52 per diluted share. In the third quarter of 2014, we recognized a benefit for adjustments to pre-existing warranties of $(29) million, or $(0.36) per diluted share. Included in the 2014 adjustments is a $36 million correction of prior-period errors, primarily related to pre-existing warranties. For more information on the errors identified, see 2014 Out-of-Period Adjustments. The impact of income taxes on the 2014 adjustments is not material due to our deferred tax valuation allowances on our U.S. deferred tax assets.In the first quarter of 2013, we recorded adjustments for changes in estimates of $40 million or $0.50 per diluted share. In the second quarter of 2013, we recorded adjustments for changes in estimates of $164 million, or $2.04 per diluted share. In the third quarter of 2013, we recorded adjustments for changes in estimates of $48 million, or $0.60 per diluted share. In the fourth quarter of 2013, we recorded adjustments for changes in estimates of $152 million, or $1.89 per diluted share. The impact of income taxes on the 2013 adjustments is not material due to our deferred tax valuation allowances on our U.S. deferred tax assets. In the first quarter of 2012, we recorded adjustments for changes in estimates of $123 million, or $1.76 per diluted share. In the second quarter of 2012, we recorded adjustments for changes in estimates of $104 million, or $1.51 per diluted share. In the fourth quarter of 2012, we recorded adjustments for changes in estimates of $149 million, or $2.16 per diluted share. |

| X                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Product Warranty Accrual, Divestures
+ References
No definition available.
+ Details**Name:**nav_ProductWarrantyAccrualDivestures**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                              |
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| - Definition
Product Warranty Accrual, Preexisting Increase Decrease Per Share, Net of Tax
+ References
No definition available.
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| - Definition
Warranty Recoveries
+ References
No definition available.
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| - Definition
Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 13 -Section AReference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 605 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 13.A.4(a).Q1 Response) -URI http://asc.fasb.org/extlink&oid=27012821&loc=d3e214044-122780
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of previously reported deferred or unearned revenue that was recognized as revenue during the period. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.
+ References
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| - Definition
Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers.
+ References
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers. For classified balance sheets, represents the current portion of the liabilities (due within one year or within the normal operating cycle if longer).
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total Increase or Decrease in the standard and extended product warranty liability due to currency translation.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying value as of the balance sheet date of obligations incurred through that date and due after one year (or beyond the operating cycle if longer) for estimated claims under standard and extended warranty protection rights granted to customers.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the aggregate decrease in the liability related to payments to satisfy claims for standard and extended product warranties.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the aggregate Increase or Decrease in the liability during the reporting period for accruals related to preexisting standard and extended product warranties (including adjustments for changes in estimates).
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the aggregate increase in the liability for accruals related to standard and extended product warranties issued during the reporting period.
+ References
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