Condensed Consolidated Statements of Redeemable Noncontrolling Interest and Stockholders' Deficit - USD ($) $ in Thousands	Total	Redeemable Non Controlling Equity [Member]	Convertible Preferred Stock [Member]	Common Class A [Member]	Common Class F [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2019	$ (256,567)		$ 399,589	$ 6	$ 1	$ 235,190	$ (4,140)	$ (887,213)
Beginning balance (Shares) at Dec. 31, 2019			109,090,908	177,593,772	42,564,150
Exercises and vesting of early exercised Class A common stock options	145					145
Exercises and vesting of early exercised Class A common stock options (Shares)				442,503
Repurchase of unvested Class A common stock related to early exercised stock options (Shares)				(425,001)
Repurchase of Class A common stock	(760)					(760)
Repurchase of Class A common stock (Shares)				(114,000)
Stock-based compensation	3,462					3,462
Total other comprehensive loss	(1,903)						(1,903)
Net loss	4,664							4,664
Net loss - Temporary Equity	0
Ending balance at Mar. 31, 2020	(250,959)		$ 399,589	$ 6	$ 1	238,037	(6,043)	(882,549)
Ending balance (Shares) at Mar. 31, 2020			109,090,908	177,497,274	42,564,150
Beginning balance, Temporary Equity at Dec. 31, 2020	309	$ 309
Beginning balance at Dec. 31, 2020	(158,545)		$ 399,589	$ 6	$ 1	453,655	604	(1,012,400)
Beginning balance (Shares) at Dec. 31, 2020			109,090,908	183,800,251	42,564,150
Exercises and vesting of early exercised Class A common stock options	10,143					10,143
Exercises and vesting of early exercised Class A common stock options (Shares)				1,232,156
Repurchase of Class A common stock (Shares)				(214,509)
Stock-based compensation	29,667					29,667
Total other comprehensive loss	(721)						(721)
Net loss	(10,521)							(10,521)
Net loss - Temporary Equity	(54)	(54)
Ending balance, Temporary Equity at Mar. 31, 2021	255	$ 255
Ending balance at Mar. 31, 2021	$ (129,977)		$ 399,589	$ 6	$ 1	$ 493,465	$ (117)	$ (1,022,921)
Ending balance (Shares) at Mar. 31, 2021			109,090,908	184,817,898	42,564,150