| **Goodwill and Other Intangible assets, Net - Narrative (Details) (USD $)In Millions, unless otherwise specified**                                     | 12 Months Ended                                                                                                                | 3 Months Ended |                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------|----------------|------------------------------------------------------------------------------------------------------|
||
| **Goodwill [Line Items]**                                                                                                                              |                                                                                                                           |                |                                                                                                 |   |  |   |  |   |   |   |
| Goodwill                                                                                                                                               | $ 38us-gaap_Goodwill                                                                                                           |                | $ 184us-gaap_Goodwill                                                                                | $ 280us-gaap_Goodwill |  | $ 184us-gaap_Goodwill |  |   |   | $ 319us-gaap_Goodwill |
| Indefinite-Lived Intangible Assets (Excluding Goodwill)                                                                                                | 34us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill                                                                     |                | 46us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill                                           |   |  | 46us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill |  |   |   |   |
| Goodwill, Impairment Loss                                                                                                                              | 142us-gaap_GoodwillImpairmentLoss                                                                                              |                | 81us-gaap_GoodwillImpairmentLoss                                                                     |   |  |   |  |   |   |   |
| Amortization of Intangible Assets                                                                                                                      | 18us-gaap_AmortizationOfIntangibleAssets                                                                                       |                | 22us-gaap_AmortizationOfIntangibleAssets                                                             | 25us-gaap_AmortizationOfIntangibleAssets |  |   |  |   |   |   |
| North America Truck [Member]                                                                                                                           |                                                                                                                           |                |                                                                                                 |   |  |   |  |   |   |   |
| **Goodwill [Line Items]**                                                                                                                              |                                                                                                                           |                |                                                                                                 |   |  |   |  |   |   |   |
| Goodwill                                                                                                                                               | 0us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember                                          |                | 0us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember                | 82us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |  | 0us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |  |   |   | 82us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |
| Goodwill, Impairment Loss                                                                                                                              | 0us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember                            |                | 81us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |   |  | (77)us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |  | (4)us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |   |   |
| Brazilian Reporting Unit [Member]                                                                                                                      |                                                                                                                           |                |                                                                                                 |   |  |   |  |   |   |   |
| **Goodwill [Line Items]**                                                                                                                              |                                                                                                                           |                |                                                                                                 |   |  |   |  |   |   |   |
| Goodwill                                                                                                                                               |                                                                                                                           |                |                                                                                                 |   |  |   |  |   | 142us-gaap_Goodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |   |
| Indefinite-Lived Intangible Assets (Excluding Goodwill)                                                                                                |                                                                                                                           |                |                                                                                                 |   |  |   |  |   | 43us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |   |
| Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)                                                                                 | 7us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |                |                                                                                                 | 0us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |  | 0us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |  |   | 7us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |   |
| Goodwill, Impairment Loss                                                                                                                              | $ 142us-gaap_GoodwillImpairmentLoss/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember                                   | [1]            |                                                                                                 | $ 0us-gaap_GoodwillImpairmentLoss/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember | [1] | $ 81us-gaap_GoodwillImpairmentLoss/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember | [1] |   |   |   |
|                                                                                                                                                        |
| [1](A)For more information, see Note 8, Goodwill and Other Intangible Assets, Net, and includes $4 million related to discontinued operations in 2013. |

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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.
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