Condensed Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions		Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Non-Controlling Interests [Member]
Balance at Dec. 31, 2019		$ 6,451	$ 2	$ 4,575	$ 1,922	$ (3)	$ (45)
Balance (shares) at Dec. 31, 2019			239,000,000
Share-based compensation, net		(4)		(5)	1
Net loss		(689)			(688)		(1)
Other comprehensive income (loss)		(2)				(2)
Dividends and dividend equivalents	[1]	(106)			(106)
Distributions to noncontrolling interests		(1)					(1)
Repurchase of common stock		(66)		(66)
Repurchases of common stock (Shares)			(4,000,000)
Balance at Mar. 31, 2020		5,583	$ 2	4,504	1,129	(5)	(47)
Balance (shares) at Mar. 31, 2020			235,000,000
Balance at Dec. 31, 2019		6,451	$ 2	4,575	1,922	(3)	(45)
Balance (shares) at Dec. 31, 2019			239,000,000
Net loss		(1,226)
Other comprehensive income (loss)		(2)
Balance at Sep. 30, 2020		5,055	$ 2	4,512	595	(5)	(49)
Balance (shares) at Sep. 30, 2020			236,000,000
Balance at Mar. 31, 2020		5,583	$ 2	4,504	1,129	(5)	(47)
Balance (shares) at Mar. 31, 2020			235,000,000
Share-based compensation, net		5		4	1
Share-based compensation, net (Shares)			1,000,000
Net loss		(261)			(259)		(2)
Other comprehensive income (loss)		1				(1)
Balance at Jun. 30, 2020		5,326	$ 2	4,508	871	(6)	(49)
Balance (shares) at Jun. 30, 2020			236,000,000
Share-based compensation, net		4		4
Net loss		(276)			(276)
Other comprehensive income (loss)		1				1
Balance at Sep. 30, 2020		5,055	$ 2	4,512	595	(5)	(49)
Balance (shares) at Sep. 30, 2020			236,000,000
Balance at Dec. 31, 2020		$ 4,843	$ 2	4,519	376	(4)	(50)
Balance (shares) at Dec. 31, 2020		235,915,749	236,000,000
Share-based compensation, net				1	(1)
Net loss		$ (191)			(190)		(1)
Other comprehensive income (loss)		1				1
Balance at Mar. 31, 2021		4,653	$ 2	4,520	185	(3)	(51)
Balance (shares) at Mar. 31, 2021			236,000,000
Balance at Dec. 31, 2020		$ 4,843	$ 2	4,519	376	(4)	(50)
Balance (shares) at Dec. 31, 2020		235,915,749	236,000,000
Net loss		$ (387)
Other comprehensive income (loss)		4
Balance at Sep. 30, 2021		$ 4,468	$ 2	4,529	(16)		(47)
Balance (shares) at Sep. 30, 2021		236,479,696	236,000,000
Balance at Mar. 31, 2021		$ 4,653	$ 2	4,520	185	(3)	(51)
Balance (shares) at Mar. 31, 2021			236,000,000
Share-based compensation, net		6		5	1
Net loss		(114)			(116)		2
Balance at Jun. 30, 2021		4,545	$ 2	4,525	70	(3)	(49)
Balance (shares) at Jun. 30, 2021			236,000,000
Share-based compensation, net		4		4
Net loss		(82)			(86)		4
Other comprehensive income (loss)		3				3
Distributions to noncontrolling interests		(2)					(2)
Balance at Sep. 30, 2021		$ 4,468	$ 2	$ 4,529	$ (16)		$ (47)
Balance (shares) at Sep. 30, 2021		236,479,696	236,000,000

[1] Dividends declared per common share were $0.45 for the three months ended March 31, 2020.