Consolidated Statements of Stockholders' Deficit - USD ($) $ in Millions	Total	Common Stock [Member]	Capital in Excess of Par Value [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Deficit [Member]	Equity Attributable to Noncontrolling Interests [Member]
Balance at Dec. 31, 2014	$ (6,498)	$ 4		$ (323)	$ (7,575)	$ 1,396
Balance, shares at Dec. 31, 2014		420,478,000
Comprehensive income (loss)	2,754			58	2,129	567
Repurchase of common stock	$ (2,397)		$ (505)		(1,892)
Repurchase of common stock, shares	(31,991,000)	(31,991,000)
Share-based benefit plans	$ 523		523
Share-based benefit plans, shares		10,252,000
Distributions	(495)					(495)
Acquisition of entities with noncontrolling interests	85					85
Other	(18)		(18)
Balance at Dec. 31, 2015	(6,046)	$ 4		(265)	(7,338)	1,553
Balance, shares at Dec. 31, 2015		398,739,000
Comprehensive income (loss)	3,359			(73)	2,890	542
Repurchase of common stock	$ (2,751)		(231)		(2,520)
Repurchase of common stock, shares	(36,325,000)	(36,325,000)
Share-based benefit plans	$ 233		233
Share-based benefit plans, shares		8,122,000
Distributions	(434)					(434)
Other	6		(2)			8
Balance at Dec. 31, 2016	(5,633)	$ 4		(338)	(6,968)	1,669
Balance, shares at Dec. 31, 2016		370,536,000
Comprehensive income (loss)	2,803			60	2,216	527
Repurchase of common stock	$ (2,051)		(271)		(1,780)
Repurchase of common stock, shares	(25,092,000)	(25,092,000)
Share-based benefit plans	$ 281		281
Share-based benefit plans, shares		4,648,000
Distributions	(448)					(448)
Acquisition of entities with noncontrolling interests	63					63
Other	(10)		$ (10)
Balance at Dec. 31, 2017	$ (4,995)	$ 4		$ (278)	$ (6,532)	$ 1,811
Balance, shares at Dec. 31, 2017		350,092,000