CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock, at Cost	Non-controlling Interests
Balance, value at Dec. 31, 2018	$ 5,267	$ 2	$ 2,667	$ 7,602	$ (59)	$ (4,996)	$ 51
Balance, shares at Dec. 31, 2018		135.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	900			858			42
Other comprehensive income (loss), net of tax	20				20
Dividends declared	(286)			(286)
Distributions to noncontrolling interest partners	(47)						(47)
Issuance of common stock under benefit plans	24		9			15
Stock-based compensation expense	56		55			1
Exercise of stock options, value	119		7			112
Exercise of stock options, shares		2.0
Shares to cover employee payroll tax withholdings on stock issued under stock-based compensation plans	(16)		(16)
Purchases of treasury stock, value	(350)					$ (350)
Purchases of treasury stock, shares		(4.0)				(3.5)
Balance, value at Dec. 31, 2019	5,687	$ 2	2,722	8,174	(39)	$ (5,218)	46
Balance, shares at Dec. 31, 2019		133.0
Balance, value at Dec. 31, 2018	77
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income	6
Distributions to noncontrolling interest partners	(7)
Balance, value at Dec. 31, 2019	76
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,484			1,431			53
Other comprehensive income (loss), net of tax	18				18
Dividends declared	(302)			(302)
Distributions to noncontrolling interest partners	(49)						(49)
Issuance of common stock under benefit plans	25		11			14
Issuance of common stock under benefit plans, sharers		1.0
Stock-based compensation expense	97		97
Exercise of stock options, value	189		26			163
Exercise of stock options, shares		2.0
Shares to cover employee payroll tax withholdings on stock issued under stock-based compensation plans	(15)		(15)
Purchases of treasury stock, value	(325)					$ (325)
Purchases of treasury stock, shares		(3.0)				(2.7)
Balance, value at Dec. 31, 2020	6,809	$ 2	2,841	9,303	(21)	$ (5,366)	50
Balance, shares at Dec. 31, 2020		133.0
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income	15
Distributions to noncontrolling interest partners	(9)
Net income	2,067			1,995			72
Other comprehensive income (loss), net of tax	7				7
Dividends declared	(307)			(307)
Distributions to noncontrolling interest partners	(83)						(83)
Issuance of common stock under benefit plans	26		(21)			47
Stock-based compensation expense	79		79
Exercise of stock options, value	129		20			109
Exercise of stock options, shares		2.0
Shares to cover employee payroll tax withholdings on stock issued under stock-based compensation plans	(22)		(10)			(12)
Purchases of treasury stock, value	(2,222)					$ (2,222)
Purchases of treasury stock, shares		(16.0)				(16.0)
Retirement of treasury stock	0		(649)	(3,342)		$ 3,991
Balance, value at Dec. 31, 2021	6,483	$ 2	$ 2,260	$ 7,649	$ (14)	$ (3,453)	$ 39
Balance, shares at Dec. 31, 2021		119.0
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income	13
Distributions to noncontrolling interest partners	$ (16)