| **Goodwill and Other Intangible assets, Net Changes in Carrying Amounts of Goodwill (Details) (USD $)In Millions, unless otherwise specified**                                                                                                                                | 3 Months Ended                                                                                       | 12 Months Ended                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------|
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| **Goodwill [Roll Forward]**                                                                                                                                                                                                                                                   |                                                                                                 |                                                                                                |   |   |   |  |
| Goodwill                                                                                                                                                                                                                                                                      |                                                                                                 |                                                                                                | $ 184us-gaap_Goodwill | $ 280us-gaap_Goodwill | $ 319us-gaap_Goodwill |  |
| Goodwill, Translation Adjustments                                                                                                                                                                                                                                             |                                                                                                 |                                                                                                | (4)us-gaap_GoodwillTranslationAdjustments | (12)us-gaap_GoodwillTranslationAdjustments | (33)us-gaap_GoodwillTranslationAdjustments |  |
| Goodwill, Subsequent Recognition of Deferred Tax Asset                                                                                                                                                                                                                        |                                                                                                 |                                                                                                |   | (3)us-gaap_GoodwillSubsequentRecognitionOfDeferredTaxAsset | (6)us-gaap_GoodwillSubsequentRecognitionOfDeferredTaxAsset | [1] |
| Goodwill, Impairment Loss                                                                                                                                                                                                                                                     |                                                                                                 |                                                                                                | (142)us-gaap_GoodwillImpairmentLoss | (81)us-gaap_GoodwillImpairmentLoss |   |  |
| Goodwill                                                                                                                                                                                                                                                                      | 184us-gaap_Goodwill                                                                                  |                                                                                                | 38us-gaap_Goodwill | 184us-gaap_Goodwill | 280us-gaap_Goodwill |  |
| North America Truck [Member]                                                                                                                                                                                                                                                  |                                                                                                 |                                                                                                |   |   |   |  |
| **Goodwill [Roll Forward]**                                                                                                                                                                                                                                                   |                                                                                                 |                                                                                                |   |   |   |  |
| Goodwill                                                                                                                                                                                                                                                                      |                                                                                                 |                                                                                                | 0us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | 82us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | 82us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |  |
| Goodwill, Translation Adjustments                                                                                                                                                                                                                                             |                                                                                                 |                                                                                                | 0us-gaap_GoodwillTranslationAdjustments/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | 0us-gaap_GoodwillTranslationAdjustments/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | 0us-gaap_GoodwillTranslationAdjustments/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |  |
| Goodwill, Subsequent Recognition of Deferred Tax Asset                                                                                                                                                                                                                        |                                                                                                 |                                                                                                |   | (1)us-gaap_GoodwillSubsequentRecognitionOfDeferredTaxAsset/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | 0us-gaap_GoodwillSubsequentRecognitionOfDeferredTaxAsset/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | [1] |
| Goodwill, Impairment Loss                                                                                                                                                                                                                                                     | 77us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | 4us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | 0us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | (81)us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |   |  |
| Goodwill                                                                                                                                                                                                                                                                      | 0us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember                |                                                                                                | 0us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | 0us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember | 82us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaTruckMember |  |
| North America Parts [Member]                                                                                                                                                                                                                                                  |                                                                                                 |                                                                                                |   |   |   |  |
| **Goodwill [Roll Forward]**                                                                                                                                                                                                                                                   |                                                                                                 |                                                                                                |   |   |   |  |
| Goodwill                                                                                                                                                                                                                                                                      |                                                                                                 |                                                                                                | 38us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember | 38us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember | 38us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember |  |
| Goodwill, Translation Adjustments                                                                                                                                                                                                                                             |                                                                                                 |                                                                                                | 0us-gaap_GoodwillTranslationAdjustments/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember | 0us-gaap_GoodwillTranslationAdjustments/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember | 0us-gaap_GoodwillTranslationAdjustments/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember |  |
| Goodwill, Subsequent Recognition of Deferred Tax Asset                                                                                                                                                                                                                        |                                                                                                 |                                                                                                |   | 0us-gaap_GoodwillSubsequentRecognitionOfDeferredTaxAsset/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember | 0us-gaap_GoodwillSubsequentRecognitionOfDeferredTaxAsset/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember | [1] |
| Goodwill, Impairment Loss                                                                                                                                                                                                                                                     |                                                                                                 |                                                                                                | 0us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember | 0us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember |   |  |
| Goodwill                                                                                                                                                                                                                                                                      | 38us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember               |                                                                                                | 38us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember | 38us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember | 38us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_NorthAmericaPartsMember |  |
| Global Operations [Member]                                                                                                                                                                                                                                                    |                                                                                                 |                                                                                                |   |   |   |  |
| **Goodwill [Roll Forward]**                                                                                                                                                                                                                                                   |                                                                                                 |                                                                                                |   |   |   |  |
| Goodwill                                                                                                                                                                                                                                                                      |                                                                                                 |                                                                                                | 146us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember | 160us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember | 199us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember |  |
| Goodwill, Translation Adjustments                                                                                                                                                                                                                                             |                                                                                                 |                                                                                                | (4)us-gaap_GoodwillTranslationAdjustments/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember | (12)us-gaap_GoodwillTranslationAdjustments/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember | (33)us-gaap_GoodwillTranslationAdjustments/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember |  |
| Goodwill, Subsequent Recognition of Deferred Tax Asset                                                                                                                                                                                                                        |                                                                                                 |                                                                                                |   | (2)us-gaap_GoodwillSubsequentRecognitionOfDeferredTaxAsset/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember | (6)us-gaap_GoodwillSubsequentRecognitionOfDeferredTaxAsset/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember | [1] |
| Goodwill, Impairment Loss                                                                                                                                                                                                                                                     |                                                                                                 |                                                                                                | (142)us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember | 0us-gaap_GoodwillImpairmentLoss/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember |   |  |
| Goodwill                                                                                                                                                                                                                                                                      | $ 146us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember             |                                                                                                | $ 0us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember | $ 146us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember | $ 160us-gaap_Goodwill/ us-gaap_StatementBusinessSegmentsAxis= nav_GlobalOperationsMember |  |
|                                                                                                                                                                                                                                                                               |
| [1]Adjustments to goodwill primarily result from the tax benefit attributable to the amortization of tax deductible goodwill in excess of goodwill recorded for financial statement purposes as measured in the IIAA balance sheet immediately after its acquisition in 2005. |

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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
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266
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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
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of (increase) decrease to an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from the subsequent recognition of deferred tax assets.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267
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| - Definition
Amount of increase (decrease) from foreign currency translation adjustments 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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