Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Common Stock Held in Treasury	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interest
Beginning balance at Dec. 31, 2018	$ 3,258	$ 6	$ 1,253	$ 21,217	$ (17,545)	$ (1,677)	$ 4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	597			597
Common stock issued for stock-based compensation	1		(8)		9
Stock-based compensation expense	10		10
Repurchases of common stock	(375)				(375)
Dividends declared	(326)			(326)
Other comprehensive income (loss)	35					35
Ending balance at Mar. 31, 2019	3,200	6	1,255	21,488	(17,911)	(1,642)	4
Beginning balance at Dec. 31, 2019	3,030	6	1,304	22,403	(18,982)	(1,705)	4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	566			566
Common stock issued for stock-based compensation	5		(3)		8
Stock-based compensation expense	9		9
Repurchases of common stock	(706)				(706)
Dividends declared	(338)			(338)
Other comprehensive income (loss)	(278)					(278)
Noncontrolling interest	(4)		(1)				(3)
Ending balance at Mar. 31, 2020	$ 2,284	$ 6	$ 1,309	$ 22,631	$ (19,680)	$ (1,983)	$ 1