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	8			8
Net income	145				145
Dividends paid on common stock	(79)				(79)
Dividends paid on preferred stock	(8)				(8)
Purchase of common stock	(16)					(16)
Purchase of common stock, shares		(1,343,366)
Other comprehensive income (loss), net of tax	(97)						(97)
Balance at Mar. 31, 2021	6,795	$ 5	503	6,103	552	(246)	(122)
Balance, shares at Mar. 31, 2021		465,074,384
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				(26)		26
Shares issued for restricted stock, net of forfeitures, shares		2,910,435
Compensation expense related to restricted stock awards	7			7
Net income	155				155
Dividends paid on common stock	(79)				(79)
Dividends paid on preferred stock	(8)				(8)
Purchase of common stock	(11)					(11)
Purchase of common stock, shares		901,934
Other comprehensive income (loss), net of tax	(199)						(199)
Balance at Mar. 31, 2022	$ 6,909	$ 5	$ 503	$ 6,107	$ 809	$ (231)	$ (284)
Balance, shares at Mar. 31, 2022		467,024,144