Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2020	$ 10,561	$ 0	$ 937	$ (4,089)	$ 7,174	$ 6,466	$ 73
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchased under buyback programs	0
Stock-based compensation	(3)			(24)	21
Net income (loss)	97					97
Other comprehensive income (loss)	39						39
Dividends paid	(23)					(23)
Ending balance at Mar. 31, 2021	10,671	0	937	(4,113)	7,195	6,540	112
Beginning balance at Dec. 31, 2021	10,686	0	937	(4,825)	7,221	7,271	82
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchased under buyback programs	(592)			(592)
Stock-based compensation	12			55	(43)
Net income (loss)	1,304					1,304
Other comprehensive income (loss)	8						8
Dividends paid	(52)					(52)
Ending balance at Mar. 31, 2022	$ 11,366	$ 0	$ 937	$ (5,362)	$ 7,178	$ 8,523	$ 90