Noninterest Income - Client Investment 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
Sweep money market fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	56	7	80	18
Asset management fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	15	8	25	16
Repurchase agreement fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	12	0	13	1
Client investment fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 83	$ 15	$ 118	$ 35