Mortgage Banking Activities, Mortgage Banking Noninterest Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Servicing Asset at Amortized Cost [Line Items]
Contractually specified servicing fees, late charges and ancillary fees	$ 629	$ 684	$ 1,909	$ 2,100
Unreimbursed direct servicing costs	(35)	(70)	(116)	(284)
Servicing fees	594	614	1,793	1,816
Amortization	(62)	(61)	(185)	(159)
Changes due to collection/realization of expected cash flows	(290)	(507)	(934)	(1,580)
Net servicing fees	242	46	674	77
Changes in fair value of MSRs due to valuation inputs or assumptions	750	275	3,223	1,057
Market-related valuation changes to MSRs, net of hedge results	(113)	99	(266)	(52)
Total net servicing income	129	145	408	25
Net gains on mortgage loan originations/sales	195	1,114	896	3,896
Total mortgage banking noninterest income	324	1,259	1,304	3,921
Total changes in fair value	460	(232)	2,289	(523)
Mortgage Banking Activities Textual [Abstract]
Net derivative gains (losses) from economic hedges related to mortgage loans held for sale and derivative loan commitments	568	142	2,600	987
Not designated as hedging instrument [Member]
Servicing Asset at Amortized Cost [Line Items]
Net derivative gains (losses) from economic hedges	(863)	(176)	(3,489)	(1,109)
Commercial mortgage servicing [Member] | Amortized [Member]
Mortgage Banking Activities Textual [Abstract]
MSR impairment (reversal of impairment)	$ 0	$ (4)	$ (4)	$ (41)