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, 2015	$ 4,713	$ 2	$ 2,481	$ 6,199	$ (38)	$ (3,960)	$ 29
Balance, shares at Dec. 31, 2015		143.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	113			103			10
Other comprehensive income (loss), net of taxes	(2)				(2)
Dividends declared	(57)			(57)
Distributions to noncontrolling interests	(9)						(9)
Issuance of common stock under benefit plans, value	5		1			4
Stock-based compensation expense	18		17			1
Exercise of stock options, value	7					7
Shares to cover employee payroll tax withholdings on stock issued under stock-based compensation plans	(8)		(8)
Purchases of treasury stock, value	(115)					$ (115)
Purchases of treasury stock, shares		(2.0)				(1.7)
Balance, value at Mar. 31, 2016	4,665	$ 2	2,491	6,245	(40)	$ (4,063)	30
Balance, shares at Mar. 31, 2016		141.0
Balance, Value at Dec. 31, 2015	70
Redeemable Non-controlling Interest [Abstract]
Net income	2
Balance, Value at Mar. 31, 2016	72
Balance, value at Dec. 31, 2016	4,660	$ 2	2,545	6,613	(72)	(4,460)	32
Balance, shares at Dec. 31, 2016		137.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	174			164			10
Other comprehensive income (loss), net of taxes	4				4
Dividends declared	(62)			(62)
Distributions to noncontrolling interests	(9)						(9)
Issuance of common stock under benefit plans, value	5		2			3
Issuance of common stock under benefit plans, shares		1.0
Stock-based compensation expense	17		16			1
Exercise of stock options, value	46		1			45
Exercise of stock options, shares		1.0
Shares to cover employee payroll tax withholdings on stock issued under stock-based compensation plans	(22)		(22)
Purchases of treasury stock, value	(150)					$ (150)
Purchases of treasury stock, shares		(2.0)				(1.6)
Balance, value at Mar. 31, 2017	4,663	$ 2	$ 2,542	$ 6,715	$ (68)	$ (4,561)	$ 33
Balance, shares at Mar. 31, 2017		137.0
Balance, Value at Dec. 31, 2016	77
Redeemable Non-controlling Interest [Abstract]
Net income	1
Balance, Value at Mar. 31, 2017	$ 78