| **Segment Reporting - Sales and Revenues to External Customers & Long-lived Assets (Details) (USD $)In Millions, unless otherwise specified** | 3 Months Ended | 12 Months Ended |
|---------------------------------------------------------------------------------------------------------------------------------------------------|----------------|-----------------|
||
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  | $ 2,751        |                 | $ 2,861 | $ 2,526 | $ 2,637 | $ 3,179 |  | $ 3,246 | $ 3,261 | $ 3,009 | $ 10,775 |  | $ 12,695 |  | $ 13,641 |
| UNITED STATES                                                                                                                                     |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  |           |                 |   |   |   |   |  |   |   |   | 7,122 |  | 8,822 |  | 9,329 |
| Long-lived assets                                                                                                                                 | 1,467          | [1]             |   |   |   | 1,519 | [1] |   |   |   | 1,467 | [1] | 1,519 | [1] |   |
| CANADA                                                                                                                                            |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  |           |                 |   |   |   |   |  |   |   |   | 791 |  | 949 |  | 1,071 |
| Long-lived assets                                                                                                                                 | 26             | [1]             |   |   |   | 28 | [1] |   |   |   | 26 | [1] | 28 | [1] |   |
| MEXICO                                                                                                                                            |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  |           |                 |   |   |   |   |  |   |   |   | 694 |  | 728 |  | 1,002 |
| Long-lived assets                                                                                                                                 | 157            | [1]             |   |   |   | 94 | [1] |   |   |   | 157 | [1] | 94 | [1] |   |
| BRAZIL                                                                                                                                            |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  |           |                 |   |   |   |   |  |   |   |   | 1,121 |  | 1,066 |  | 1,190 |
| Long-lived assets                                                                                                                                 | 376            | [1]             |   |   |   | 445 | [1] |   |   |   | 376 | [1] | 445 | [1] |   |
| Other Countries [Member]                                                                                                                          |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  |           |                 |   |   |   |   |  |   |   |   | 1,047 |  | 1,130 |  | 1,049 |
| Long-lived assets                                                                                                                                 | 37             | [1]             |   |   |   | 25 | [1] |   |   |   | 37 | [1] | 25 | [1] |   |
| Truck [Member]                                                                                                                                    |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  |           |                 |   |   |   |   |  |   |   |   | 6,738 |  | 8,705 |  | 9,312 |
| Parts [Member]                                                                                                                                    |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  |           |                 |   |   |   |   |  |   |   |   | 2,906 |  | 2,886 |  | 2,901 |
| Engine [Member]                                                                                                                                   |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  |           |                 |   |   |   |   |  |   |   |   | 973 |  | 936 |  | 1,228 |
| Financial Services Operations [Member]                                                                                                            |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| External sales and revenues, net                                                                                                                  |           |                 |   |   |   |   |  |   |   |   | $ 158 |  | $ 168 |  | $ 200 |
| Customer Concentration Risk [Member]                                                                                                              |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| **Revenues from External Customers and Long-Lived Assets [Line Items]**                                                                           |           |                 |   |   |   |   |  |   |   |   |   |  |   |  |   |
| Concentration Risk, Percentage                                                                                                                    |           |                 |   |   |   |   |  |   |   |   | 13.00% |  |   |  |   |
|                                                                                                                                                   |
| [1](A)Long-lived assets consist of Property and equipment, net, Goodwill, and Intangible assets, net.                                             |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).
+ References
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| X                                                                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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