Parent Company Financial Information - Parent Company Condensed Income and Comprehensive Income Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income:
Interest and other income from subsidiaries	$ 203	$ 324	$ 108
Expenses:
Interest Expense	768	1,722	2,096
Other expenses	15,116	14,897	7,934
Income tax benefit	(1,556)	(981)	(782)
Net income	6,437	4,492	3,237
OCI	(2,320)	1,560	871
Total comprehensive income	4,117	6,052	4,108
Parent Company
Income:
Total dividends from subsidiaries	4,250	2,805	1,685
Interest and other income from subsidiaries	143	170	217
Other income	(26)	12	0
Total income	4,367	2,987	1,902
Expenses:
Interest Expense	258	333	475
Other expenses	125	174	250
Total expenses	383	507	725
Income before income taxes and equity in undistributed earnings of subsidiaries	3,984	2,480	1,177
Income tax benefit	26	56	92
Income before equity in undistributed earnings of subsidiaries	4,010	2,536	1,269
Equity in undistributed earnings of subsidiaries in excess of dividends from subsidiaries	2,427	1,956	1,968
Net income	6,437	4,492	3,237
OCI	(2,320)	1,560	871
Total comprehensive income	4,117	6,052	4,108
Parent Company | Nonbank
Income:
Total dividends from subsidiaries	100	5	35
Parent Company | Banking
Income:
Total dividends from subsidiaries	$ 4,150	$ 2,800	$ 1,650