Noninterest Income - Summary of Other Noninterest Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Trading Activity, Gains and Losses, Net [Line Items]
Revenue from contracts with customers	$ 306	$ 285	$ 633	$ 506
Net gains on revaluation of foreign currency instruments, net of foreign exchange forward contracts	6	0	5	0
Other service revenue	15	8	31	11
Other	42	16	72	27
Fund management fees
Trading Activity, Gains and Losses, Net [Line Items]
Revenue from contracts with customers	$ 21	$ 8	$ 36	$ 16