Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Preferred Stock (Par Value: $0.01)	Common Stock (Par Value: $0.01)	Paid-in Capital in excess of Par	Retained Earnings	Treasury Stock, at Cost	Accumulated Other Comprehensive Loss, Net of Tax
Beginning balance (in shares) at Dec. 31, 2021	465,015,643
Beginning balance at Dec. 31, 2021	$ 7,044	$ 503	$ 5	$ 6,126	$ 741	$ (246)	$ (85)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for restricted stock, net of forfeitures (in shares)	2,939,365
Shares issued for restricted stock, net of forfeitures	$ 0			(27)		27
Compensation expense related to restricted stock awards	15			15
Net income	326				326
Dividends paid on common stock	(158)				(158)
Dividends paid on preferred stock	$ (16)				(16)
Purchase of common stock (in shares)	(1,711,930)
Purchase of common stock	$ (19)					(19)
Other comprehensive loss, net of tax	$ (368)						(368)
Ending balance (in shares) at Jun. 30, 2022	466,243,078
Ending balance at Jun. 30, 2022	$ 6,824	503	5	6,114	893	(238)	(453)
Beginning balance (in shares) at Mar. 31, 2022	467,024,144
Beginning balance at Mar. 31, 2022	$ 6,909	503	5	6,107	809	(231)	(284)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for restricted stock, net of forfeitures (in shares)	28,930
Shares issued for restricted stock, net of forfeitures	$ 0
Compensation expense related to restricted stock awards	7			7
Net income	171				171
Dividends paid on common stock	(79)				(79)
Dividends paid on preferred stock	$ (8)				(8)
Purchase of common stock (in shares)	(809,996)
Purchase of common stock	$ (7)					(7)
Other comprehensive loss, net of tax	$ (169)						(169)
Ending balance (in shares) at Jun. 30, 2022	466,243,078
Ending balance at Jun. 30, 2022	$ 6,824	503	5	6,114	893	(238)	(453)
Beginning balance (in shares) at Dec. 31, 2022	681,217,334
Beginning balance at Dec. 31, 2022	$ 8,824	503	7	8,130	1,041	(237)	(620)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance and exercise of FDIC Equity appreciation instrument (in shares)	39,032,006
Issuance and exercise of FDIC Equity appreciation instrument	$ 85			85
Shares issued for restricted stock, net of forfeitures (in shares)	3,393,046
Shares issued for restricted stock, net of forfeitures	$ 0			(31)		31
Compensation expense related to restricted stock awards	20			20
Net income	2,419				2,419
Dividends paid on common stock	(239)				(239)
Dividends paid on preferred stock	$ (16)				(16)
Purchase of common stock (in shares)	(1,166,631)
Purchase of common stock	$ (11)					(11)
Other comprehensive loss, net of tax	$ (22)						(22)
Ending balance (in shares) at Jun. 30, 2023	722,475,755
Ending balance at Jun. 30, 2023	$ 11,060	503	7	8,204	3,205	(217)	(642)
Beginning balance (in shares) at Mar. 31, 2023	722,150,297
Beginning balance at Mar. 31, 2023	$ 10,782	503	7	8,197	2,923	(219)	(629)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for restricted stock, net of forfeitures (in shares)	515,635
Shares issued for restricted stock, net of forfeitures	$ 0			(4)		4
Compensation expense related to restricted stock awards	11			11
Net income	413				413
Dividends paid on common stock	(123)				(123)
Dividends paid on preferred stock	$ (8)				(8)
Purchase of common stock (in shares)	(190,177)
Purchase of common stock	$ (2)					(2)
Other comprehensive loss, net of tax	$ (13)						(13)
Ending balance (in shares) at Jun. 30, 2023	722,475,755
Ending balance at Jun. 30, 2023	$ 11,060	$ 503	$ 7	$ 8,204	$ 3,205	$ (217)	$ (642)