Goodwill and Mortgage Servicing Rights - Mortgage Servicing Rights (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Mortgage servicing rights activity
Fair value at beginning of period	$ 5,494	$ 3,276	$ 4,699
MSR activity:
Originations of MSRs	798	1,659	944
Purchase of MSRs	1,400	1,363	248
Disposition of MSRs	(822)	(114)	(176)
Net additions/(dispositions)	1,376	2,908	1,016
Changes due to collection/realization of expected cash flows	(936)	(788)	(899)
Changes in valuation due to inputs and assumptions:
Changes due to market interest rates and other	2,022	404	(1,568)
Changes in valuation due to other inputs and assumptions:
Projected cash flows (e.g., cost to service)	14	109	(54)
Discount rates	0	0	199
Prepayment model changes and other	3	(415)	(117)
Total changes in valuation due to other inputs and assumptions	17	(306)	28
Total changes in valuation due to inputs and assumptions	2,039	98	(1,540)
Fair value at December 31,	7,973	5,494	3,276
Change in unrealized gains/(losses) included in income related to MSRs held at December 31,	$ 2,039	$ 98	$ (1,540)
Contractually Specified Servicing Fee Income Statement Of Income Or Comprehensive Income Extensible Enumeration Not Disclosed Flag	Contractual service fees, late fees and other ancillary fees included in income	Contractual service fees, late fees and other ancillary fees included in income	Contractual service fees, late fees and other ancillary fees included in income
Contractual service fees, late fees and other ancillary fees included in income	$ 1,535	$ 1,298	$ 1,325
Third-party mortgage loans serviced at December 31,	584,000	520,000	448,000
Servicer advances, net of an allowance for uncollectible amounts, at December 31,	$ 800	$ 1,600	$ 1,800