Goodwill and Mortgage Servicing Rights - Mortgage Servicing Rights (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Mortgage Servicing Rights [Roll Forward]
Fair value at beginning of period	$ 7,973	$ 5,494
MSR activity:
Originations of MSRs	32	415
Purchase of MSRs	(1)	715
Disposition of MSRs	2	(57)
Net additions/(dispositions)	33	1,073
Changes due to collection/realization of expected cash flows	(240)	(232)
Changes in valuation due to inputs and assumptions:
Changes due to market interest rates and other	(22)	894
Changes in valuation due to other inputs and assumptions:
Projected cash flows (e.g., cost to service)	0	0
Discount rates	0	0
Prepayment model changes and other	11	65
Total changes in valuation due to other inputs and assumptions	11	65
Total changes in valuation due to inputs and assumptions	(11)	959
Fair value at end of period	7,755	7,294
Changes in unrealized gains/(losses) included in income related to MSRs	(11)	959
Contractual service fees, late fees and other ancillary fees included in income	388	370
Third-party mortgage loans serviced	577,000	576,000
Servicer advances, net of an allowance for uncollectible amounts	$ 671	$ 1,426