CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions	Total controlling interest shareholders' equity	Shares	Additional paid-in capital	Accumulated deficit Period of Adoption, Adjustment	Accumulated deficit	Accumulated other comprehensive loss	Noncontrolling interest	Total
Balance at Dec. 31, 2019	$ 11,862	$ 59	$ 13,424		$ (1,297)	$ (324)	$ 5	$ 11,867
Increase (Decrease) in Shareholders' Equity
Share-based compensation	15		15					15
Issuance of shares		1	(1)
Net loss attributable to controlling interest					(889)			(889)
Other comprehensive income (loss) attributable to controlling interest						(5)		(5)
Total comprehensive loss attributable to controlling interest	(894)							(894)
Total comprehensive income attributable to noncontrolling interest							1
Total comprehensive loss								(893)
Other, net	(2)							(2)
Balance at Jun. 30, 2020	10,981	60	13,438	$ (2)	(2,188)	(329)	6	10,987
Balance at Dec. 31, 2019	11,862	59	13,424		(1,297)	(324)	5	11,867
Balance at Dec. 31, 2020	11,432	60	13,501		(1,866)	(263)	3	11,435
Balance at Mar. 31, 2020	11,469	60	13,431		(1,691)	(331)	6	11,475
Increase (Decrease) in Shareholders' Equity
Share-based compensation	7		7					7
Net loss attributable to controlling interest					(497)			(497)
Other comprehensive income (loss) attributable to controlling interest						2		2
Total comprehensive loss attributable to controlling interest	(495)							(495)
Total comprehensive loss								(495)
Balance at Jun. 30, 2020	10,981	60	13,438	$ (2)	(2,188)	(329)	6	10,987
Balance at Dec. 31, 2020	11,432	60	13,501		(1,866)	(263)	3	11,435
Increase (Decrease) in Shareholders' Equity
Share-based compensation	14		14					14
Issuance of shares	66	2	64					66
Net loss attributable to controlling interest					(202)			(202)
Other comprehensive income (loss) attributable to controlling interest						(1)		(1)
Total comprehensive loss attributable to controlling interest	(203)							(203)
Total comprehensive income attributable to noncontrolling interest							1
Total comprehensive loss								(202)
Other, net	(1)		(1)					(1)
Balance at Jun. 30, 2021	11,308	62	13,578		(2,068)	(264)	4	11,312
Balance at Mar. 31, 2021	11,336	60	13,508		(1,965)	(267)	4	11,340
Increase (Decrease) in Shareholders' Equity
Share-based compensation	7		7					7
Issuance of shares	66	2	64					66
Net loss attributable to controlling interest					(103)			(103)
Other comprehensive income (loss) attributable to controlling interest						3		3
Total comprehensive loss attributable to controlling interest	(100)							(100)
Total comprehensive loss								(100)
Other, net	(1)		(1)					(1)
Balance at Jun. 30, 2021	$ 11,308	$ 62	$ 13,578		$ (2,068)	$ (264)	$ 4	$ 11,312