Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income
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	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
Beginning balance at Dec. 31, 2021	10,686	0	937	(4,825)	7,221	7,271	82
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,270
Other comprehensive income (loss)	12
Ending balance at Jun. 30, 2022	11,532	0	937	(6,118)	7,186	9,433	94
Beginning balance at Mar. 31, 2022	11,366	0	937	(5,362)	7,178	8,523	90
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchased under buyback programs	(760)			(760)
Stock-based compensation	12			4	8
Net income	966					966
Other comprehensive income (loss)	4						4
Dividends paid	(56)					(56)
Ending balance at Jun. 30, 2022	11,532	0	937	(6,118)	7,186	9,433	94
Beginning balance at Dec. 31, 2022	11,397	0	937	(7,512)	7,203	10,663	106
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchased under buyback programs	(334)			(334)
Excise tax on shares repurchased	(3)			(3)
Stock-based compensation	(19)			35	(54)
Net income	417					417
Other comprehensive income (loss)	(7)						(7)
Dividends paid	(63)					(63)
Ending balance at Mar. 31, 2023	11,388	0	937	(7,814)	7,149	11,017	99
Beginning balance at Dec. 31, 2022	11,397	0	937	(7,512)	7,203	10,663	106
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	704
Other comprehensive income (loss)	(12)
Ending balance at Jun. 30, 2023	11,244	0	937	(8,188)	7,159	11,242	94
Beginning balance at Mar. 31, 2023	11,388	0	937	(7,814)	7,149	11,017	99
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares repurchased under buyback programs	(372)			(372)
Excise tax on shares repurchased	(3)			(3)
Stock-based compensation	11			1	10
Net income	287					287
Other comprehensive income (loss)	(5)						(5)
Dividends paid	(62)					(62)
Ending balance at Jun. 30, 2023	$ 11,244	$ 0	$ 937	$ (8,188)	$ 7,159	$ 11,242	$ 94