v3.20.4

Fair Value Measurements And Disclosure (Notional Amount Of Our Outstanding Derivative Positions) (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Derivative [Line Items] |  |
Notional amounts of outstanding derivative positions | $ 40,835 | $ 46,947
Interest rate swaps |  |
Derivative [Line Items] |  |
Notional amounts of outstanding derivative positions | 0 | 853
Cross-currency swaps |  |
Derivative [Line Items] |  |
Notional amounts of outstanding derivative positions | 40,745 | 42,325
Interest rate locks |  |
Derivative [Line Items] |  |
Notional amounts of outstanding derivative positions | 0 | 3,500
Foreign exchange contracts |  |
Derivative [Line Items] |  |
Notional amounts of outstanding derivative positions | $ 90 | $ 269

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