Noninterest Income - Credit Card 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]
Card interchange fees, net	$ 32	$ 26	$ 62	$ 49
Revenue from contracts with customers	368	306	720	633
Revenue not from contract with customer	(6)	455	159	872
Total credit card fees	40	31	77	59
Merchant service fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6	4	11	8
Card service fees
Disaggregation of Revenue [Line Items]
Revenue not from contract with customer	$ 2	$ 1	$ 4	$ 2