| **Segment Reporting - Narrative (Details) $ in Millions** | 3 Months Ended | 12 Months Ended |
|-----------------------------------------------------------|----------------|-----------------|
||
| **Segment Reporting [Abstract]**                          |           |            |   |   |   |   |   |   |   |   |   |
| Concentration Risk, Customer                              |           |            |   |   |   |   |   |   | 0 | 0 | 0 |
| **Segment Reporting Information [Line Items]**            |           |            |   |   |   |   |   |   |   |   |   |
| Number Of Segments | segments                             | 4              |            |   |   |   |   |   |   | 4 |   |   |
| Intersegment sales and revenues                           |           |            |   |   |   |   |   |   | $ 1 | $ 0 | $ 0 |
| Sales and revenues, net                                   | $ 2,063        | $ 2,086         | $ 2,197 | $ 1,765 | $ 2,488 | $ 2,538 | $ 2,693 | $ 2,421 | 8,111 | 10,140 | 10,806 |
| Financial Services Operations                             |           |            |   |   |   |   |   |   |   |   |   |
| **Segment Reporting Information [Line Items]**            |           |            |   |   |   |   |   |   |   |   |   |
| Investment Income, Interest                               |           |            |   |   |   |   |   |   | 167 | 175 | 170 |
| Intersegment sales and revenues                           |           |            |   |   |   |   |   |   | 100 | 96 | 79 |
| Sales and revenues, net                                   |           |            |   |   |   |   |   |   | 235 | 241 | 232 |
| North America Truck [Member]                              |           |            |   |   |   |   |   |   |   |   |   |
| **Segment Reporting Information [Line Items]**            |           |            |   |   |   |   |   |   |   |   |   |
| Intersegment sales and revenues                           |           |            |   |   |   |   |   |   | 132 | 158 | 218 |
| Sales and revenues, net                                   |           |            |   |   |   |   |   |   | 5,403 | 7,213 | 7,473 |
| North America Parts [Member]                              |           |            |   |   |   |   |   |   |   |   |   |
| **Segment Reporting Information [Line Items]**            |           |            |   |   |   |   |   |   |   |   |   |
| Intersegment sales and revenues                           |           |            |   |   |   |   |   |   | 29 | 38 | 58 |
| Sales and revenues, net                                   |           |            |   |   |   |   |   |   | 2,427 | 2,513 | 2,551 |
| Corporate And Eliminations [Member]                       |           |            |   |   |   |   |   |   |   |   |   |
| **Segment Reporting Information [Line Items]**            |           |            |   |   |   |   |   |   |   |   |   |
| Intersegment sales and revenues                           |           |            |   |   |   |   |   |   | (305) | (343) | (390) |
| Sales and revenues, net                                   |           |            |   |   |   |   |   |   | $ (295) | $ (333) | $ (390) |

| X                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Intersegment sales and revenues
+ References
No definition available.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Description of risks that arise due to the volume of business transacted with a particular customer. At a minimum, the description informs financial statement users of the general nature of the risk, but excludes "Information about Major Customers" that may be disclosed elsewhere (for instance, segment disclosures).
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6351-108592Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6404-108592Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6327-108592
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.7(b)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.
+ References
No definition available.
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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
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688
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| - References
No definition available.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
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