Derivative Financial Instruments - Cumulative Basis Adjustments for Fair Value Hedges (Details) - USD ($) $ in Millions |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Short-term debt | ||
| Amounts recorded in the Consolidated Balance Sheet related to cumulative basis adjustments for fair value hedges | ||
| Carrying amount of the hedged item | $ (1,302) | |
| Cumulative hedging adjustments included in the carrying amount-assets/(liabilities) | (2) | |
| Long-term debt | ||
| Amounts recorded in the Consolidated Balance Sheet related to cumulative basis adjustments for fair value hedges | ||
| Carrying amount of the hedged item | (2,097) | $ (3,411) |
| Cumulative hedging adjustments included in the carrying amount-assets/(liabilities) | (424) | (440) |
| Hedging adjustments on discontinued hedging relationships | $ (353) | $ (404) |