Mortgage Banking Activities, Mortgage Banking Noninterest Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Servicing Asset at Amortized Cost [Line Items]
Contractually specified servicing fees, late charges and ancillary fees	$ 635	$ 724
Unreimbursed direct servicing costs	(24)	(124)
Servicing fees	611	600
Amortization	(59)	(65)
Changes due to collection/realization of expected cash flows	(357)	(585)
Net servicing fees	195	(50)
Changes in fair value of MSRs due to valuation inputs or assumptions	1,605	1,591
Market-related valuation changes to MSRs, net of hedge results	(41)	(49)
Total net servicing income	154	(99)
Net gains on mortgage loan originations/sales	539	1,425
Total mortgage banking noninterest income	693	1,326
Total changes in fair value	1,248	1,006
Mortgage Banking Activities Textual [Abstract]
Net derivative gains (losses) from economic hedges related to mortgage loans held for sale and derivative loan commitments	1,300	1,300
Not designated as hedging instrument [Member]
Servicing Asset at Amortized Cost [Line Items]
Net derivative gains (losses) from economic hedges	(1,646)	(1,640)
Commercial mortgage servicing [Member] | Amortized [Member]
Mortgage Banking Activities Textual [Abstract]
MSR impairment	$ (4)	$ 0