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]
Balances 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
Comprehensive income (loss)	4,381			(8)	3,787	602
Repurchase of common stock	$ (1,530)	$ (1)	(103)		(1,426)
Repurchase of common stock, shares	(14,070,000)	(14,070,000)
Share-based benefit plans	$ 115		115
Share-based benefit plans, shares		6,873,000
Cash dividends declared ($1.40 share)	(496)				(496)
Distributions	(441)					(441)
Acquisition of entities with noncontrolling interests	60					60
Reclassification of stranded tax effects				(95)	95
Other	(12)		$ (12)
Balance at Dec. 31, 2018	$ (2,918)	$ 3		$ (381)	$ (4,572)	$ 2,032
Balance, shares at Dec. 31, 2018		342,895,000