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	22			22
Net income	478				478
Dividends paid on common stock	(237)				(237)
Dividends paid on preferred stock	$ (25)				(25)
Purchase of common stock (in shares)	(1,818,952)
Purchase of common stock	$ (19)					(19)
Other comprehensive loss, net of tax	$ (517)						(517)
Ending balance (in shares) at Sep. 30, 2022	466,136,056
Ending balance at Sep. 30, 2022	$ 6,746	503	5	6,121	957	(238)	(602)
Beginning balance (in shares) at Jun. 30, 2022	466,243,078
Beginning balance at Jun. 30, 2022	$ 6,824	503	5	6,114	893	(238)	(453)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for restricted stock, net of forfeitures	0
Compensation expense related to restricted stock awards	7			7
Net income	152				152
Dividends paid on common stock	(80)				(80)
Dividends paid on preferred stock	$ (8)				(8)
Purchase of common stock (in shares)	(107,022)
Purchase of common stock	$ 0
Other comprehensive loss, net of tax	$ (149)						(149)
Ending balance (in shares) at Sep. 30, 2022	466,136,056
Ending balance at Sep. 30, 2022	$ 6,746	503	5	6,121	957	(238)	(602)
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)	3,436,504
Shares issued for restricted stock, net of forfeitures	$ 0			(31)		31
Compensation expense related to restricted stock awards	33			33
Net income	2,626				2,626
Dividends paid on common stock	(364)				(364)
Dividends paid on preferred stock	$ (25)				(25)
Purchase of common stock (in shares)	(1,200,587)
Purchase of common stock	$ (11)					(11)
Other comprehensive loss, net of tax	$ (175)						(175)
Ending balance (in shares) at Sep. 30, 2023	722,485,257
Ending balance at Sep. 30, 2023	$ 10,993	503	7	8,217	3,278	(217)	(795)
Beginning balance (in shares) at Jun. 30, 2023	722,475,755
Beginning balance at Jun. 30, 2023	$ 11,060	503	7	8,204	3,205	(217)	(642)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for restricted stock, net of forfeitures (in shares)	43,458
Shares issued for restricted stock, net of forfeitures	$ 0
Compensation expense related to restricted stock awards	13			13
Net income	207				207
Dividends paid on common stock	(125)				(125)
Dividends paid on preferred stock	$ (9)				(9)
Purchase of common stock (in shares)	(33,956)
Purchase of common stock	$ 0
Other comprehensive loss, net of tax	$ (153)						(153)
Ending balance (in shares) at Sep. 30, 2023	722,485,257
Ending balance at Sep. 30, 2023	$ 10,993	$ 503	$ 7	$ 8,217	$ 3,278	$ (217)	$ (795)