CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN CONTINGENTLY REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ DEFICIT - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income
Temporary equity, beginning balance (in shares) at Dec. 31, 2019	343,000,000
Temporary equity, beginning balance at Dec. 31, 2019	$ 2,750
Temporary equity, ending balance (in shares) at Mar. 31, 2020	343,000,000
Temporary equity, ending balance at Mar. 31, 2020	$ 2,750
Beginning balance (in shares) at Dec. 31, 2019	100,000,000
Beginning balance at Dec. 31, 2019	$ (375)	$ 0	$ 293	$ (668)	$ 0
Stockholders' Deficit
Net loss	$ (177)			(177)
Ending balance (in shares) at Mar. 31, 2020	100,000,000
Ending balance at Mar. 31, 2020	$ (552)	0	293	(845)	0
Temporary equity, beginning balance (in shares) at Dec. 31, 2019	343,000,000
Temporary equity, beginning balance at Dec. 31, 2019	$ 2,750
Contingently Redeemable Convertible Preferred Stock
Shares issued (in shares)	161,394,452
Shares issued	$ 2,500
Temporary equity, ending balance (in shares) at Sep. 30, 2020	504,000,000
Temporary equity, ending balance at Sep. 30, 2020	$ 5,250
Beginning balance (in shares) at Dec. 31, 2019	100,000,000
Beginning balance at Dec. 31, 2019	$ (375)	$ 0	293	(668)	0
Stockholders' Deficit
New shares issued (in shares)		0
Net loss	$ (665)
Ending balance (in shares) at Sep. 30, 2020	100,000,000
Ending balance at Sep. 30, 2020	$ (1,037)	$ 0	296	(1,333)	0
Temporary equity, beginning balance (in shares) at Mar. 31, 2020	343,000,000
Temporary equity, beginning balance at Mar. 31, 2020	$ 2,750
Temporary equity, ending balance (in shares) at Jun. 30, 2020	343,000,000
Temporary equity, ending balance at Jun. 30, 2020	$ 2,750
Beginning balance (in shares) at Mar. 31, 2020	100,000,000
Beginning balance at Mar. 31, 2020	$ (552)	0	293	(845)	0
Stockholders' Deficit
Warrants Issued	3		3
Net loss	$ (200)			(200)
Ending balance (in shares) at Jun. 30, 2020	100,000,000
Ending balance at Jun. 30, 2020	$ (749)	0	296	(1,045)	0
Contingently Redeemable Convertible Preferred Stock
Shares issued (in shares)	161,000,000
Shares issued	$ 2,500
Temporary equity, ending balance (in shares) at Sep. 30, 2020	504,000,000
Temporary equity, ending balance at Sep. 30, 2020	$ 5,250
Stockholders' Deficit
Net loss	$ (288)			(288)
Ending balance (in shares) at Sep. 30, 2020	100,000,000
Ending balance at Sep. 30, 2020	$ (1,037)	0	296	(1,333)	0
Temporary equity, beginning balance (in shares) at Dec. 31, 2020	503,951,340
Temporary equity, beginning balance at Dec. 31, 2020	$ 5,244
Contingently Redeemable Convertible Preferred Stock
Shares issued (in shares)	72,000,000
Shares issued	$ 2,650
Temporary equity, ending balance (in shares) at Mar. 31, 2021	576,000,000
Temporary equity, ending balance at Mar. 31, 2021	$ 7,894
Beginning balance (in shares) at Dec. 31, 2020	101,327,571
Beginning balance at Dec. 31, 2020	$ (1,384)	0	302	(1,686)	0
Stockholders' Deficit
Shares issued	1		1
Net loss	$ (414)			(414)
Ending balance (in shares) at Mar. 31, 2021	101,000,000
Ending balance at Mar. 31, 2021	$ (1,797)	0	303	(2,100)	0
Temporary equity, beginning balance (in shares) at Dec. 31, 2020	503,951,340
Temporary equity, beginning balance at Dec. 31, 2020	$ 5,244
Contingently Redeemable Convertible Preferred Stock
Shares issued (in shares)	71,913,170
Shares issued	$ 2,700
Temporary equity, ending balance (in shares) at Sep. 30, 2021	575,864,510
Temporary equity, ending balance at Sep. 30, 2021	$ 7,894
Beginning balance (in shares) at Dec. 31, 2020	101,327,571
Beginning balance at Dec. 31, 2020	$ (1,384)	$ 0	302	(1,686)	0
Stockholders' Deficit
New shares issued (in shares)		321,304
Shares issued		$ 4
Net loss	$ (2,227)
Ending balance (in shares) at Sep. 30, 2021	101,518,666
Ending balance at Sep. 30, 2021	$ (3,607)	0	306	(3,913)	0
Temporary equity, beginning balance (in shares) at Mar. 31, 2021	576,000,000
Temporary equity, beginning balance at Mar. 31, 2021	$ 7,894
Temporary equity, ending balance (in shares) at Jun. 30, 2021	576,000,000
Temporary equity, ending balance at Jun. 30, 2021	$ 7,894
Beginning balance (in shares) at Mar. 31, 2021	101,000,000
Beginning balance at Mar. 31, 2021	$ (1,797)	0	303	(2,100)	0
Stockholders' Deficit
Shares issued	2		2
Net loss	$ (580)			(580)
Ending balance (in shares) at Jun. 30, 2021	101,000,000
Ending balance at Jun. 30, 2021	$ (2,375)	0	305	(2,680)	0
Temporary equity, ending balance (in shares) at Sep. 30, 2021	575,864,510
Temporary equity, ending balance at Sep. 30, 2021	$ 7,894
Stockholders' Deficit
New shares issued (in shares)	1,000,000
Shares issued	$ 1		1
Net loss	$ (1,233)			(1,233)
Ending balance (in shares) at Sep. 30, 2021	101,518,666
Ending balance at Sep. 30, 2021	$ (3,607)	$ 0	$ 306	$ (3,913)	$ 0