Condensed Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions		Total	Cumulative Effect of Change in Accounting Principle [member]	Common Stock [member]	Additional Paid-in Capital [member]	Retained Earnings [member]	Retained Earnings [member] Cumulative Effect of Change in Accounting Principle [member]	Accumulated Other Comprehensive (Loss) Income [member]	Non-Controlling Interests [member]
Balance at Dec. 31, 2018		$ 5,586		$ 2	$ 3,589	$ 2,047		$ (6)	$ (46)
Balance (shares) at Dec. 31, 2018				201,000,000
Share-based compensation, net		(1)			(1)
Net income (loss)		97				96			1
Dividends and dividend equivalents	[1]	(91)				(91)
Distributions to noncontrolling interests		(3)							(3)
Balance at Mar. 31, 2019		5,580	$ (8)	$ 2	3,588	2,044	$ (8)	(6)	(48)
Balance (shares) at Mar. 31, 2019				201,000,000
Balance at Dec. 31, 2018		5,586		$ 2	3,589	2,047		(6)	(46)
Balance (shares) at Dec. 31, 2018				201,000,000
Net income (loss)		190
Other comprehensive income (loss)		(2)
Balance at Sep. 30, 2019		6,453		$ 2	4,572	1,931		(8)	(44)
Balance (shares) at Sep. 30, 2019				240,000,000
Balance at Mar. 31, 2019		5,580	$ (8)	$ 2	3,588	2,044	$ (8)	(6)	(48)
Balance (shares) at Mar. 31, 2019				201,000,000
Share-based compensation, net		3			3
Share-based compensation, net (Shares)				1,000,000
Net income (loss)		84				82			2
Other comprehensive income (loss)		1						1
Dividends and dividend equivalents	[1]	(92)				(92)
Balance at Jun. 30, 2019		5,576		$ 2	3,591	2,034		(5)	(46)
Balance (shares) at Jun. 30, 2019				202,000,000
Issuance of common stock		978			978
Issuance of common stock (Shares)				38,000,000
Share-based compensation, net		3			3
Net income (loss)		9				5			4
Other comprehensive income (loss)		(3)						(3)
Dividends and dividend equivalents	[1]	(108)				(108)
Distributions to noncontrolling interests		(2)							(2)
Balance at Sep. 30, 2019		6,453		$ 2	4,572	1,931		(8)	(44)
Balance (shares) at Sep. 30, 2019				240,000,000
Balance at Dec. 31, 2019		$ 6,451		$ 2	4,575	1,922		(3)	(45)
Balance (shares) at Dec. 31, 2019		239,386,877		239,000,000
Share-based compensation, net		$ (4)			(5)	1
Net income (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		239,386,877		239,000,000
Net income (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		235,613,445		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 income (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 income (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		235,613,445		236,000,000

[1] Dividends declared per common share were $0.45 for the three months ended March 31, 2020, March 31, 2019, June 30, 2019 and September 30, 2019, respectively.