Noninterest Income - Credit Card Fees (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 1,314	$ 1,057	$ 880
Revenue not from contracts with customer	1,424	783	341
Total credit card fees	131	98	119
Credit interchange fees, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	108	76	94
Merchant service fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	18	18	18
Card service fees
Disaggregation of Revenue [Line Items]
Revenue not from contracts with customer	$ 5	$ 4	$ 7