| **Leases (Details) - USD ($) $ in Millions** | Mar. 31, 2019 | Dec. 31, 2018 |
|----------------------------------------------|---------------|---------------|
| **Loans and Leases Receivable Disclosure**   |          |          |
| Remaining nine months of 2019                | $ 2,445       |          |
| 2019                                         |          | $ 3,053       |
| 2020                                         | 2,324         | 2,076         |
| 2021                                         | 1,295         | 1,104         |
| 2022                                         | 570           | 470           |
| 2023                                         | 228           | 173           |
| Thereafter                                   | 82            | 64            |
| Total                                        | 6,944         | 6,940         |
| Guaranteed residual value                    | 435           | 458           |
| Unguaranteed residual value                  | 851           | 857           |
| Unearned income                              | (646)         | (647)         |
| Total                                        | 7,584         | 7,608         |
| Retail leases                                |          |          |
| **Loans and Leases Receivable Disclosure**   |          |          |
| Remaining nine months of 2019                | 2,423         |          |
| 2019                                         |          | 3,024         |
| 2020                                         | 2,303         | 2,055         |
| 2021                                         | 1,282         | 1,092         |
| 2022                                         | 564           | 465           |
| 2023                                         | 226           | 171           |
| Thereafter                                   | 80            | 62            |
| Total                                        | 6,878         | 6,869         |
| Guaranteed residual value                    | 396           | 416           |
| Unguaranteed residual value                  | 849           | 854           |
| Unearned income                              | (640)         | (640)         |
| Total                                        | 7,483         | 7,499         |
| Wholesale leases                             |          |          |
| **Loans and Leases Receivable Disclosure**   |          |          |
| Remaining nine months of 2019                | 22            |          |
| 2019                                         |          | 29            |
| 2020                                         | 21            | 21            |
| 2021                                         | 13            | 12            |
| 2022                                         | 6             | 5             |
| 2023                                         | 2             | 2             |
| Thereafter                                   | 2             | 2             |
| Total                                        | 66            | 71            |
| Guaranteed residual value                    | 39            | 42            |
| Unguaranteed residual value                  | 2             | 3             |
| Unearned income                              | (6)           | (7)           |
| Total                                        | $ 101         | $ 109         |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.
+ References
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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.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Present value of lease payments not yet received by lessor and amount expected to be derived from underlying asset, following end of lease term guaranteed by lessee or other third party unrelated to lessor, from sales-type and direct financing leases.
+ References
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| - Definition
Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in fifth fiscal year following latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest statement of financial position date.
+ References
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| - Definition
Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in fourth fiscal year following latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in the next fiscal year following latest fiscal year. Excludes interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date.
+ References
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| - Definition
Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in remainder of the fiscal year following latest fiscal year. Excludes interim and annual period when interim periods are reported on a rolling approach, from latest statement of financial position date.
+ References
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| - Definition
Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases after fifth fiscal year following latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest statement of financial position date.
+ References
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| - Definition
Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in third fiscal year following latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest statement of financial position date.
+ References
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| - Definition
Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in second fiscal year following latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest statement of financial position date.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of residual asset covered by residual value guarantee under sales-type lease. Excludes guarantee considered to be lease payments for lessor.
+ References
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| - Definition
Present value expected to be derived from underlying asset following end of lease term not guaranteed by lessee or other third party unrelated to lessor.
+ References
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