CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Accumulated Deficit	Accumulated Other Comprehensive Loss	Common Stock Held in Treasury	Total Stockholders’ Equity	Noncontrolling Interests
Balance (in shares) at Dec. 31, 2016		1,574				129
Balance at Dec. 31, 2016	$ 9,257	$ 157	$ 26,690	$ (16,540)	$ (548)	$ (3,708)	$ 6,051	$ 3,206
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercised and issued stock-based awards (in shares)		4
Exercised and issued stock-based awards	6	$ 1	5				6
Stock-based compensation, including tax benefit and the tender of shares	42		56			$ (15)	41	1
Stock-based compensation, including tax benefit and the tender of shares (in shares)						1
Dividends	(173)			1			1	(174)
Net loss attributable to common stockholders	1,817			1,817			1,817
Net income attributable to noncontrolling interests, including discontinued operations	278							278
Other comprehensive (loss) income	69				61		61	8
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	2,164
Balance (in shares) at Dec. 31, 2017		1,578				130
Balance at Dec. 31, 2017	11,296	$ 158	26,751	(14,722)	(487)	$ (3,723)	7,977	3,319
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercised and issued stock-based awards (in shares)		1
Exercised and issued stock-based awards	8		8				8
Stock-based compensation, including tax benefit and the tender of shares	66		70			$ (4)	66	0
Dividends	(569)		(291)				(291)	(278)
Net loss attributable to common stockholders	2,602			2,602			2,602
Net income attributable to noncontrolling interests, including discontinued operations	292							292
Other comprehensive (loss) income	(34)				(33)		(33)	(1)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	2,860
Balance (in shares) at Dec. 31, 2018		1,579				130
Balance at Dec. 31, 2018	17,892	$ 158	26,013	(12,041)	(605)	$ (3,727)	9,798	8,094
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	4,231		(525)		(6)		(531)	4,762
Cumulative Effect of New Accounting Principle in Period of Adoption				79	(79)
Exercised and issued stock-based awards (in shares)		3
Exercised and issued stock-based awards	1		1				1
Stock-based compensation, including tax benefit and the tender of shares	44		50			$ (7)	43	1
Stock-based compensation, including tax benefit and the tender of shares (in shares)						1
Dividends	(364)		(291)				(291)	(73)
Changes in noncontrolling interests	(12)		(1)				(1)	(11)
Net loss attributable to common stockholders	(239)			(239)			(239)
Net income attributable to noncontrolling interests, including discontinued operations	50							50
Other comprehensive (loss) income	(68)				(71)		(71)	3
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(257)
Balance (in shares) at Dec. 31, 2019		1,582				131
Balance at Dec. 31, 2019	17,448	$ 158	25,830	$ (12,280)	$ (676)	$ (3,734)	9,298	8,150
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments to Additional Paid in Capital, Other	(22)		(22)				(22)
Proceeds from (Payments to) Noncontrolling Interests	$ 166		$ 80				$ 80	$ 86