| **Loss Per Share Attributable to Navistar International Corporation - Narrative (Details) (USD $)**                  | 3 Months Ended                                                                                                                                 | 6 Months Ended                                                                                                                              | 1 Months Ended                                                                                                                                                                                                                                                                                         | 12 Months Ended                                                                                                                                |                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                             |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Shares of Warrants Unwound                                                                                           | 1,939,376nav_SharesofWarrantsUnwound                                                                                                           | 6,523,319nav_SharesofWarrantsUnwound                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount                                      | 16,000,000us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount                                                        | 24,000,000us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount                                                     | 16,000,000us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount                                                                                                                                                                                                                | 27,300,000us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount                                                        |                                                                                                                                                                                                                                                                                                 |   |   |
| Shares related to warrants                                                                                           |                                                                                                                                           | 4,800,000nav_SharesRelatedToWarrants                                                                                                        |                                                                                                                                                                                                                                                                                                   | 8,100,000nav_SharesRelatedToWarrants                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Three Point Zero Percent Senior Subordinated Convertible Notes [Member]                                              |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                             |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Shares of Warrants Unwound                                                                                           | 1,939,376nav_SharesofWarrantsUnwound/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember            | 6,523,319nav_SharesofWarrantsUnwound/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember         |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Class of Warrant or Right, Outstanding                                                                               |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   | 2,900,000us-gaap_ClassOfWarrantOrRightOutstanding/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember |
| Shares related to convertible notes                                                                                  |                                                                                                                                           | 3,300,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember |                                                                                                                                                                                                                                                                                                   | 7,300,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember    |                                                                                                                                                                                                                                                                                                 |   |   |
| Three Point Zero Percent Senior Subordinated Convertible Notes [Member] | Convertible Debt Securities [Member]       |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                             |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Debt Instrument, Convertible, Conversion Ratio                                                                       |                                                                                                                                           |                                                                                                                                        | 19.891us-gaap_DebtInstrumentConvertibleConversionRatio1/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Debt Instrument Convertible Conversion Ratio Basis                                                                   |                                                                                                                                           |                                                                                                                                        | 1,000nav_DebtInstrumentConvertibleConversionRatioBasis/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember    |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Option Indexed to Issuer's Equity, Strike Price                                                                      |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           | $ 50.27us-gaap_OptionIndexedToIssuersEquityStrikePrice1/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember |   |   |
| Investment Warrants, Exercise Price                                                                                  |                                                                                                                                           |                                                                                                                                        | 60.14invest_InvestmentWarrantsExercisePrice/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember               |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Four Point Five Zero Senior Subordinated Convertible Notes [Member]                                                  |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                             |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Shares related to convertible notes                                                                                  | 3,400,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember        | 3,400,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember     | 3,400,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember                                                                                                                                                                | 3,400,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember        |                                                                                                                                                                                                                                                                                                 |   |   |
| Four Point Five Zero Senior Subordinated Convertible Notes [Member] | Convertible Debt Securities [Member]           |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                             |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Debt Instrument, Convertible, Conversion Ratio                                                                       |                                                                                                                                           |                                                                                                                                        | 17.1233us-gaap_DebtInstrumentConvertibleConversionRatio1/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember      |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Debt Instrument Convertible Conversion Ratio Basis                                                                   |                                                                                                                                           |                                                                                                                                        | 1,000nav_DebtInstrumentConvertibleConversionRatioBasis/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember        |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Debt Instrument, Convertible, Conversion Price                                                                       |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   | 58.40us-gaap_DebtInstrumentConvertibleConversionPrice1/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember |
| Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member]                                        |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                             |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Debt Instrument, Convertible, Conversion Ratio                                                                       |                                                                                                                                           |                                                                                                                                        | 18.4946us-gaap_DebtInstrumentConvertibleConversionRatio1/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember                                                                                                                                             |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Option Indexed to Issuer's Equity, Strike Price                                                                      |                                                                                                                                           |                                                                                                                                        | 54.07us-gaap_OptionIndexedToIssuersEquityStrikePrice1/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember                                                                                                                                                |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Shares related to convertible notes                                                                                  | 7,600,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember |                                                                                                                                        | 7,600,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember                                                                                                                                                         | 3,800,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember |                                                                                                                                                                                                                                                                                                 | 7,600,000nav_SharesRelatedToConvertibleNotes/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember |   |
| Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member] | Convertible Debt Securities [Member] |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                             |                                                                                                                                           |                                                                                                                                        |                                                                                                                                                                                                                                                                                                   |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |
| Debt Instrument Convertible Conversion Ratio Basis                                                                   |                                                                                                                                           |                                                                                                                                        | 1,000nav_DebtInstrumentConvertibleConversionRatioBasis/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis= us-gaap_ConvertibleDebtSecuritiesMember/ us-gaap_DebtInstrumentAxis= nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember |                                                                                                                                           |                                                                                                                                                                                                                                                                                                 |   |   |

| X                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Exercise price of the warrants.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt Instrument Convertible Conversion Ratio Basis
+ References
No definition available.
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| X                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Shares of Warrants Unwound
+ References
No definition available.
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| - Definition
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Shares related to warrants
+ References
No definition available.
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of warrants or rights outstanding.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The price per share of the conversion feature embedded in the debt instrument.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Exercise or strike price stated in the contract for options indexed to the issuer's equity shares.
+ References
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