Derivatives and Hedging Activities - Fair Value of Derivative Assets by Type (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Credit Derivatives [Line Items]
Derivative assets before collateral	$ 1,438	$ 1,735
Plus(Less): Related collateral	86	63
Total derivative assets	1,524	1,798
Interest rate
Credit Derivatives [Line Items]
Derivative assets before collateral	858	1,448
Foreign exchange
Credit Derivatives [Line Items]
Derivative assets before collateral	55	52
Commodity
Credit Derivatives [Line Items]
Derivative assets before collateral	492	178
Credit
Credit Derivatives [Line Items]
Derivative assets before collateral	0	(1)
Other
Credit Derivatives [Line Items]
Derivative assets before collateral	$ 33	$ 58