| **Financial Instruments and Commodity Contracts - Income Statement Location (Details) (USD $)In Millions, unless otherwise specified** | 12 Months Ended                                                                                                                                                                                         |
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| **Derivative Instruments, Gain (Loss) [Line Items]**                                                                                   |                                                                                                                                                                                                    |   |   |
| Derivative Instruments, Gain (Loss) Recognized in Income, Net                                                                          | $ 4us-gaap_DerivativeGainLossOnDerivativeNet                                                                                                                                                            | $ (2)us-gaap_DerivativeGainLossOnDerivativeNet | $ (11)us-gaap_DerivativeGainLossOnDerivativeNet |
| Foreign currency contracts | Other Income Expense Net [Member]                                                                         |                                                                                                                                                                                                    |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                                                                                   |                                                                                                                                                                                                    |   |   |
| Derivative Instruments, Gain (Loss) Recognized in Income, Net                                                                          | (1)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember/ us-gaap_IncomeStatementLocationAxis= nav_OtherIncomeExpenseNetMember         | (4)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember/ us-gaap_IncomeStatementLocationAxis= nav_OtherIncomeExpenseNetMember | (4)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember/ us-gaap_IncomeStatementLocationAxis= nav_OtherIncomeExpenseNetMember |
| Cross currency swaps | Other Income Expense Net [Member]                                                                               |                                                                                                                                                                                                    |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                                                                                   |                                                                                                                                                                                                    |   |   |
| Derivative Instruments, Gain (Loss) Recognized in Income, Net                                                                          | 3us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_CrossCurrencyInterestRateContractMember/ us-gaap_IncomeStatementLocationAxis= nav_OtherIncomeExpenseNetMember | 0us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_CrossCurrencyInterestRateContractMember/ us-gaap_IncomeStatementLocationAxis= nav_OtherIncomeExpenseNetMember | 1us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_CrossCurrencyInterestRateContractMember/ us-gaap_IncomeStatementLocationAxis= nav_OtherIncomeExpenseNetMember |
| Interest Rate Cap [Member] | Interest Expense [Member]                                                                                 |                                                                                                                                                                                                    |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                                                                                   |                                                                                                                                                                                                    |   |   |
| Derivative Instruments, Gain (Loss) Recognized in Income, Net                                                                          | 1us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateCapMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_InterestExpenseMember                     | 0us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateCapMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_InterestExpenseMember | 0us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateCapMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_InterestExpenseMember |
| Commodity Contract [Member] | Cost of Sales [Member]                                                                                   |                                                                                                                                                                                                    |   |   |
| **Derivative Instruments, Gain (Loss) [Line Items]**                                                                                   |                                                                                                                                                                                                    |   |   |
| Derivative Instruments, Gain (Loss) Recognized in Income, Net                                                                          | $ (1)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_CommodityContractMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_CostOfSalesMember                   | $ (2)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_CommodityContractMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_CostOfSalesMember | $ (8)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_CommodityContractMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_CostOfSalesMember |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
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| - Definition
Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5618551-113959Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959
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