| **Discontinued Operations - Narrative (Details) (USD $)In Millions, unless otherwise specified** | 12 Months Ended                                                                                      | 1 Months Ended                                                                                                                                                                      | 3 Months Ended                                          |
|--------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------|
||
| **Statements of Operations for Discontinued Operations [Line Items]**                            |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| Proceeds from Divestiture of Businesses                                                          |                                                                                                 | $ 33us-gaap_ProceedsFromDivestitureOfBusinesses                                                                                                                                     |                                                    |   |   |   |
| Asset impairment charges                                                                         | 183us-gaap_AssetImpairmentCharges                                                                    | 97us-gaap_AssetImpairmentCharges                                                                                                                                                    | 16us-gaap_AssetImpairmentCharges                        |   |   |   |
| Impairment of Intangible Assets (Excluding Goodwill)                                             | 183us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill                                             | 105us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill                                                                                                                            | 44us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill |   |   |   |
| Number of Dealcors                                                                               | 1nav_NumberofDealcors                                                                                | 2nav_NumberofDealcors                                                                                                                                                               |                                                    |   |   |   |
| North America Truck [Member]                                                                     |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| **Statements of Operations for Discontinued Operations [Line Items]**                            |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| Proceeds from Divestiture of Businesses                                                          |                                                                                                 |                                                                                                                                                                                |                                                    | 16us-gaap_ProceedsFromDivestitureOfBusinesses/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |   |   |
| Asset impairment charges                                                                         | 19us-gaap_AssetImpairmentCharges/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |                                                                                                                                                                                |                                                    |   |   |   |
| MONACO                                                                                           |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| **Statements of Operations for Discontinued Operations [Line Items]**                            |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| Proceeds from Divestiture of Businesses                                                          |                                                                                                 |                                                                                                                                                                                |                                                    |   | 19us-gaap_ProceedsFromDivestitureOfBusinesses/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis= nav_WCCMember |   |
| Asset impairment charges                                                                         |                                                                                                 |                                                                                                                                                                                |                                                    |   | 24us-gaap_AssetImpairmentCharges/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis= nav_WCCMember | 28us-gaap_AssetImpairmentCharges/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis= nav_WCCMember |
| Mahindra [Member]                                                                                |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| **Statements of Operations for Discontinued Operations [Line Items]**                            |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| Gain (Loss) on Disposition of Business                                                           |                                                                                                 | 26us-gaap_GainLossOnSaleOfBusiness/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis= nav_MahindraMember              |                                                    |   |   |   |
| Bison Coach [Member]                                                                             |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| **Statements of Operations for Discontinued Operations [Line Items]**                            |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| Proceeds from Divestiture of Businesses                                                          |                                                                                                 | 16us-gaap_ProceedsFromDivestitureOfBusinesses/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis= nav_BisonCoachMember |                                                    |   |   |   |
| Workhorse Custom Chassis [Member] | North America Parts [Member]                                 |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| **Statements of Operations for Discontinued Operations [Line Items]**                            |                                                                                                 |                                                                                                                                                                                |                                                    |   |   |   |
| Impairment of Intangible Assets (Excluding Goodwill)                                             |                                                                                                 |                                                                                                                                                                                |                                                    |   |   | $ 10us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill/ dei_EntityByLocationAxis= nav_WorkhorseCustomChassisMember/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember |

| X                                                                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of Dealcors
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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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| - Definition
Gain (loss) from sale or disposal of an organization or integrated set of activities (for example, but not limited to, a partnership or corporation) engaged in providing a product or service in a commercial, industrial, or professional environment.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of an intangible asset (excluding goodwill) to fair value.
+ References
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.
+ References
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