Condensed Consolidated Statements of Equity - USD ($) $ in Millions		Total	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Equity Attributable to Common Stock	Equity Attributable to Noncontrolling Interests
Beginning balance at Dec. 31, 2018		$ (247)	$ 4,987	$ (5,342)	$ (6)	$ (361)	$ 114
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss		(60)		(55)		(55)	(5)
Contributions from noncontrolling interest holders, net		49					49
Distributions to noncontrolling interest holders		(29)					(29)
Other comprehensive income		1			1	1
Share-based compensation, net		7	7			7
Ending balance at Jun. 30, 2019		(279)	4,994	(5,397)	(5)	(408)	129
Beginning balance at Mar. 31, 2019		(289)	4,989	(5,409)	(6)	(426)	137
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss		12		12		12
Contributions from noncontrolling interest holders, net		0
Distributions to noncontrolling interest holders		(8)					(8)
Issuance of common stock		0
Other comprehensive income		1			1	1
Share-based compensation, net		5	5			5
Ending balance at Jun. 30, 2019		(279)	4,994	(5,397)	(5)	(408)	129
Beginning balance at Dec. 31, 2019	[1]	(296)	5,004	(5,370)	(23)	(389)	93
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	[1]	(2,052)		(2,067)		(2,067)	15
Contributions from noncontrolling interest holders, net							0
Distributions to noncontrolling interest holders	[1]	(32)					(32)
Share-based compensation, net		4	4			4
Ending balance at Jun. 30, 2020	[1]	(2,376)	5,008	(7,437)	(23)	(2,452)	76
Beginning balance at Mar. 31, 2020	[1]	(2,095)	5,006	(7,166)	(23)	(2,183)	88
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	[1]	(277)		(271)		(271)	(6)
Distributions to noncontrolling interest holders	[1]	(6)					(6)
Share-based compensation, net	[1]	2	2			2
Ending balance at Jun. 30, 2020	[1]	$ (2,376)	$ 5,008	$ (7,437)	$ (23)	$ (2,452)	$ 76

[1] The above tables exclude amounts related to redeemable noncontrolling interests reported in mezzanine equity. See Note 6 Joint Ventures for more information.