PARENT COMPANY FINANCIALS - Condensed Statements of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
OPERATING INCOME:
Total interest income	$ 7,060	$ 4,851	$ 5,357
OPERATING EXPENSE:
Salaries and employee benefits	2,549	2,132	2,123
Interest expense	1,048	339	771
All other expenses	585	411	419
Income tax expense (benefit)	582	658	241
NET INCOME	2,073	2,319	1,057
Total other comprehensive income (loss), net of income taxes	(3,895)	(605)	351
Total comprehensive income (loss)	(1,822)	1,714	1,408
Parent company
OPERATING INCOME:
Dividends	450	1,120	900
Interest	39	35	42
Management and service fees	69	64	54
All other operating income	1	1	1
Total interest income	605	1,279	1,041
OPERATING EXPENSE:
Salaries and employee benefits	43	36	27
Interest expense	125	119	120
All other expenses	28	28	30
Total operating expense	196	183	177
Income before income tax expense	409	1,096	864
Income tax expense (benefit)	(13)	(16)	(16)
Income before undistributed income of subsidiaries	422	1,112	880
NET INCOME	2,073	2,319	1,057
Total other comprehensive income (loss), net of income taxes	(3,895)	(605)	351
Total comprehensive income (loss)	(1,822)	1,714	1,408
Nonbank subsidiaries | Parent company
OPERATING INCOME:
Interest	3	2	4
Dividends	43	57	40
OPERATING EXPENSE:
Equity in undistributed income (losses) of subsidiaries	(73)	19	7
Bank subsidiaries | Parent company
OPERATING EXPENSE:
Equity in undistributed income (losses) of subsidiaries	$ 1,724	$ 1,188	$ 170