Derivatives - Derivative Instruments Included in the Consolidated Balance Sheets (Parenthetical) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Amount of variation margin payment applied to derivative asset contracts	$ 623	$ 249
Amount of variation margin payment applied to derivative liability contracts	488	$ 23
Nondesignated | Customer Accommodation | Interest Rate Contract
Derivatives, Fair Value [Line Items]
Amount of variation margin payment applied to derivative asset contracts	40
Amount of variation margin payment applied to derivative liability contracts	$ 493