Goodwill and Mortgage Servicing Rights - Mortgage Servicing Rights (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Mortgage Servicing Rights [Roll Forward]
Fair value at beginning of period	$ 7,294	$ 4,470	$ 5,494	$ 3,276
MSR activity:
Originations of MSRs	181	419	596	823
Purchase of MSRs	160	395	875	574
Disposition of MSRs	(614)	(25)	(671)	(24)
Net additions/(dispositions)	(273)	789	800	1,373
Changes due to collection/realization of expected cash flows	(236)	(182)	(468)	(369)
Changes in valuation due to inputs and assumptions:
Changes due to market interest rates and other	653	(500)	1,547	336
Changes in valuation due to other inputs and assumptions:
Projected cash flows (e.g., cost to service)	0	1	0	(23)
Discount rates	0	0	0	0
Prepayment model changes and other	1	(29)	66	(44)
Total changes in valuation due to other inputs and assumptions	1	(28)	66	(67)
Total changes in valuation due to inputs and assumptions	654	(528)	1,613	269
Fair value at end of period	7,439	4,549	7,439	4,549
Changes in unrealized gains/(losses) included in income related to MSRs	654	(528)	1,613	269
Contractual service fees, late fees and other ancillary fees included in income	395	307	765	598
Third-party mortgage loans serviced	576,000	465,000	576,000	465,000
Servicer advances, net of an allowance for uncollectible amounts	$ 1,200	$ 1,700	$ 1,200	$ 1,700