| **Loss Per Share Attributable to Navistar International Corporation - Narrative (Details) (USD $)** | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 1 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended |           | 3 Months Ended | 1 Months Ended |
|-----------------------------------------------------------------------------------------------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|-----------|----------------|----------------|
||
| **Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]**            |           |           |           |           |           |           |           |           |           |           |           |      |           |           |   |   |   |   |   |   |
| Debt Instrument, Convertible, Conversion Ratio                                                      |           |           |           |           | 17.1233        |           |           |           |           |           | 19.891         |      |           |           |   | 18.4946 |   |   |   |   |
| Debt Instrument Convertible Conversion Ratio Basis                                                  |           |           |           |           | $ 1,000        |           |           |           |           |           | $ 1,000        |      |           |           |   |   | $ 1,000 |   |   |   |
| Option Indexed to Issuer's Equity, Strike Price                                                     |           |           |           |           |           |           |           |           |           | 50.27          |           |      |           |           |   |   |   |   | 54.07 | 50.27 |
| Debt Instrument, Convertible, Conversion Price                                                      |           |           |           |           | $ 58.40        |           |           |           |           |           |           |      |           |           |   |   |   |   |   |   |
| Shares of Call Options Unwound                                                                      | 8,000,000      |           |           |           |           |           |           |           |           |           |           |      |           |           |   |   |   |   |   |   |
| Investment Warrants, Exercise Price                                                                 |           |           |           |           | $ 60.14        |           |           |           |           |           |           |      |           |           |   |   |   |   |   |   |
| Shares of Warrants Unwound                                                                          | 6,523,319      |           |           |           |           |           |           |           |           |           |           |      |           |           |   |   |   |   |   |   |
| Option Indexed to Issuer's Equity, Indexed Shares                                                   |           |           |           |           |           |           |           |           |           |           |           |      |           |           |   |   |   | 11,337,870 |   | 11,337,870 |
| Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount                     | 24,000,000     | 30,000,000     | 27,300,000     | 29,000,000     |           |           |           |           |           |           |           |      |           |           |   |   |   |   |   |   |
| Shares related to warrants                                                                          | 4,800,000      | 11,300,000     | 8,100,000      | 11,300,000     |           |           |           |           |           |           |           |      |           |           |   |   |   |   |   |   |
| Shares related to convertible notes                                                                 |           |           |           |           |           | 3,300,000      | 11,300,000     | 7,300,000      | 11,300,000     |           |           | 3,400,000 | 3,400,000      | 7,600,000      | 3,800,000 |   |   |   |   |   |

| X                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Exercise price of the warrants.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                              |
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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.
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| X                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                                                                                  |
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| X                                                                                                                                                                                                                                 |
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Shares related to warrants
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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.
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The price per share of the conversion feature embedded in the debt instrument.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of issuer's shares to which the option contract is indexed.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The exercise (or strike) price stated in the contract. The fixed price at which the option holder can purchase, in the case of a call option, or sell, in the case of a put option, on the underlying security.
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| - Definition
Number of shares that have been repurchased and retired during the period.
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