Parent Company - Condensed Statements of Income and Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Non-interest revenues
Total non-interest revenues	$ 47,381	$ 42,967	$ 34,630
Interest income	19,983	12,658	9,033
Interest expense	6,849	2,763	1,283
Total revenues net of interest expense	60,515	52,862	42,380
Expenses
Salaries and employee benefits	8,067	7,252	6,240
Other	6,807	6,481	4,817
Total expenses	45,079	41,095	33,110
Income tax benefit	2,139	2,071	2,629
Net income	8,374	7,514	8,060
Net unrealized pension and other postretirement benefits, net of tax	37	52	155
Comprehensive income	8,512	7,249	8,010
Parent Company
Non-interest revenues
Other	407	388	343
Total non-interest revenues	407	388	343
Interest income	1,558	614	96
Interest expense	1,436	857	482
Total revenues net of interest expense	529	145	(43)
Expenses
Salaries and employee benefits	487	408	359
Other	408	372	346
Total expenses	895	780	705
Loss before income tax and equity in net income of subsidiaries	(366)	(635)	(748)
Income tax benefit	(163)	(244)	(248)
Equity in net income of subsidiaries and affiliates	8,577	7,905	8,560
Net income	8,374	7,514	8,060
Net unrealized pension and other postretirement benefits, net of tax	5	10	151
Other comprehensive income (loss), net	133	(275)	(201)
Comprehensive income	$ 8,512	$ 7,249	$ 8,010