| **Loss Per Share Attributable to Navistar International Corporation - Narrative (Details) (USD $)Share data in Millions, except Per Share data, unless otherwise specified** | 3 Months Ended | 9 Months Ended |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|----------------|
||
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                                                                                     |           |           |   |   |
| Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount                                                                                              | 29.5           | 26.3           | 28.9 | 28.0 |
| Shares related to warrants                                                                                                                                                   | 11.3           | 11.3           | 11.3 | 11.3 |
| Shares related to convertible notes                                                                                                                                          | 11.3           | 11.3           | 11.3 | 11.3 |
| Convertible Debt Securities [Domain]                                                                                                                                         |           |           |   |   |
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                                                                                     |           |           |   |   |
| Debt Instrument, Convertible, Conversion Ratio                                                                                                                               |           |           | 19.891 |   |
| Debt Instrument Convertible Conversion Ratio Basis                                                                                                                           |           |           | $ 1,000 |   |
| Debt Instrument, Convertible, Conversion Price                                                                                                                               | $ 50.27        |           | $ 50.27 |   |
| Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount                                                                                              |           |           | 11.3 |   |
| Warrant [Domain]                                                                                                                                                             |           |           |   |   |
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**                                                                                     |           |           |   |   |
| Investment Warrants, Exercise Price                                                                                                                                          |           |           | $ 60.14 |   |

| X                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Exercise price of the warrants.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The basis for applying ratio applied to the debt for purposes of determining the number of shares of the equity security into which the debt will be converted.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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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
The price per share of the conversion feature embedded in the debt instrument.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The ratio applied to the debt for purposes of determining the number of shares of the equity security into which the debt will be converted.
+ References
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