Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock (Par Value: $0.01)	Preferred 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
Balance at Dec. 31, 2020	$ 6,842	$ 5	$ 503	$ 6,123	$ 494	$ (258)	$ (25)
Balance, shares at Dec. 31, 2020		463,901,808
Shares issued for restricted stock, net of forfeitures				(28)		28
Shares issued for restricted stock, net of forfeitures, shares		2,515,942
Compensation expense related to restricted stock awards	24			24
Net income	446				446
Dividends paid on common stock	(237)				(237)
Dividends paid on preferred stock	(25)				(25)
Purchase of common stock	(16)					(16)
Purchase of common stock, shares		(1,396,951)
Other comprehensive income (loss), net of tax	(67)						(67)
Balance at Sep. 30, 2021	6,967	$ 5	503	6,119	678	(246)	(92)
Balance, shares at Sep. 30, 2021		465,020,799
Balance at Jun. 30, 2021	6,916	$ 5	503	6,111	617	(245)	(75)
Balance, shares at Jun. 30, 2021		465,056,962
Compensation expense related to restricted stock awards	8			8
Net income	149				149
Dividends paid on common stock	(79)				(79)
Dividends paid on preferred stock	(9)				(9)
Purchase of common stock	(1)					(1)
Purchase of common stock, shares		(36,163)
Other comprehensive income (loss), net of tax	(17)						(17)
Balance at Sep. 30, 2021	6,967	$ 5	503	6,119	678	(246)	(92)
Balance, shares at Sep. 30, 2021		465,020,799
Balance at Dec. 31, 2021	7,044	$ 5	503	6,126	741	(246)	(85)
Balance, shares at Dec. 31, 2021		465,015,643
Shares issued for restricted stock, net of forfeitures				(27)		27
Shares issued for restricted stock, net of forfeitures, shares		2,939,365
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	(19)					(19)
Purchase of common stock, shares		(1,818,952)
Other comprehensive income (loss), net of tax	(517)						(517)
Balance at Sep. 30, 2022	6,746	$ 5	503	6,121	957	(238)	(602)
Balance, shares at Sep. 30, 2022		466,136,056
Balance at Jun. 30, 2022	6,824	$ 5	503	6,114	893	(238)	(453)
Balance, shares at Jun. 30, 2022		466,243,078
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, shares		(107,022)
Other comprehensive income (loss), net of tax	(149)						(149)
Balance at Sep. 30, 2022	$ 6,746	$ 5	$ 503	$ 6,121	$ 957	$ (238)	$ (602)
Balance, shares at Sep. 30, 2022		466,136,056