Noninterest Income - Foreign Exchange Fees (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 368	$ 306	$ 720	$ 633
Revenue not from contract with customer	(6)	455	159	872
Foreign exchange fees	69	67	142	124
Spot contract commissions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	69	66	141	123
Option premium fees
Disaggregation of Revenue [Line Items]
Revenue not from contract with customer	$ 0	$ 1	$ 1	$ 1