| **Restructuring and Impairments - Schedule of Impairment Charges (Details) (USD $)In Millions, unless otherwise specified**                            | 3 Months Ended                                                                                                                 | 12 Months Ended | 3 Months Ended                                                                                                                 |
|--------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------|-----------------|--------------------------------------------------------------------------------------------------------------------------------|
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| **Restructuring Cost and Reserve [Line Items]**                                                                                                        |                                                                                                                           |                 |                                                                                                                           |  |   |   |  |   |
| Goodwill, Impairment Loss                                                                                                                              |                                                                                                                           |                 | $ 142us-gaap_GoodwillImpairmentLoss                                                                                            |  | $ 81us-gaap_GoodwillImpairmentLoss |   |  |   |
| Other Asset Impairment Charges                                                                                                                         | 20us-gaap_OtherAssetImpairmentCharges                                                                                          |                 | 34us-gaap_OtherAssetImpairmentCharges                                                                                          |  |   | 16us-gaap_OtherAssetImpairmentCharges |  |   |
| Asset impairment charges                                                                                                                               |                                                                                                                           |                 | 183us-gaap_AssetImpairmentCharges                                                                                              |  | 97us-gaap_AssetImpairmentCharges | 16us-gaap_AssetImpairmentCharges |  |   |
| Brazilian Reporting Unit [Member]                                                                                                                      |                                                                                                                           |                 |                                                                                                                           |  |   |   |  |   |
| **Restructuring Cost and Reserve [Line Items]**                                                                                                        |                                                                                                                           |                 |                                                                                                                           |  |   |   |  |   |
| Goodwill, Impairment Loss                                                                                                                              | 81us-gaap_GoodwillImpairmentLoss/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember                                      | [1]             | 142us-gaap_GoodwillImpairmentLoss/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember                                     | [1] |   | 0us-gaap_GoodwillImpairmentLoss/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember | [1] |   |
| Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)                                                                                 | 0us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |                 | 7us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |  |   | 0us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |  | 7us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |
| Asset impairment charges                                                                                                                               |                                                                                                                           |                 |                                                                                                                           |  |   |   |  | 149us-gaap_AssetImpairmentCharges/ nav_ReportingUnitAxis= nav_BrazilianReportingUnitMember |
| Discontinued Operations [Member]                                                                                                                       |                                                                                                                           |                 |                                                                                                                           |  |   |   |  |   |
| **Restructuring Cost and Reserve [Line Items]**                                                                                                        |                                                                                                                           |                 |                                                                                                                           |  |   |   |  |   |
| Asset impairment charges                                                                                                                               |                                                                                                                           |                 | 0us-gaap_AssetImpairmentCharges/ us-gaap_StatementOperatingActivitiesSegmentAxis= us-gaap_SegmentDiscontinuedOperationsMember  |  | 4us-gaap_AssetImpairmentCharges/ us-gaap_StatementOperatingActivitiesSegmentAxis= us-gaap_SegmentDiscontinuedOperationsMember | 28us-gaap_AssetImpairmentCharges/ us-gaap_StatementOperatingActivitiesSegmentAxis= us-gaap_SegmentDiscontinuedOperationsMember |  |   |
| Impairment charges [Member]                                                                                                                            |                                                                                                                           |                 |                                                                                                                           |  |   |   |  |   |
| **Restructuring Cost and Reserve [Line Items]**                                                                                                        |                                                                                                                           |                 |                                                                                                                           |  |   |   |  |   |
| Asset impairment charges                                                                                                                               |                                                                                                                           |                 | $ 183us-gaap_AssetImpairmentCharges/ nav_ImpairmentTypeAxis= nav_ImpairmentchargesMember                                       |  | $ 105us-gaap_AssetImpairmentCharges/ nav_ImpairmentTypeAxis= nav_ImpairmentchargesMember | $ 44us-gaap_AssetImpairmentCharges/ nav_ImpairmentTypeAxis= nav_ImpairmentchargesMember |  |   |
|                                                                                                                                                        |
| [1](A)For more information, see Note 8, Goodwill and Other Intangible Assets, Net, and includes $4 million related to discontinued operations in 2013. |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The charge against earnings resulting from the write down of long lived assets other than goodwill due to the difference between the carrying value and lower fair value.
+ References
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| X                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                          |
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| X                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**nav_ReportingUnitAxis=nav_BrazilianReportingUnitMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementOperatingActivitiesSegmentAxis=us-gaap_SegmentDiscontinuedOperationsMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |