Condensed Consolidated Statements of Stockholder's Equity (Deficit) - USD ($) $ in Thousands	Total	Redeemable Convertible Preferred Stock	Accumulated Other Comprehensive Income (Loss)	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2019	$ (111,963)				$ 5,525	$ (117,488)
Beginning balance, Shares at Dec. 31, 2019				1,426,641
Redeemable convertible preferred stock, Beginning balance, Shares at Dec. 31, 2019		113,145,900
Redeemable convertible preferred stock, Beginning balance at Dec. 31, 2019		$ 110,995
Exercise of stock options	156				156
Exercise of stock options, Shares				49,031
Stock-based compensation	116				116
Repurchase of common stock	(202)				(202)
Vested stock option settlement	(728)				(728)
Net loss	(11,912)					(11,912)
Ending balance at Mar. 31, 2020	(124,533)				4,867	(129,400)
Ending balance, Shares at Mar. 31, 2020				1,475,672
Redeemable convertible preferred stock, Beginning balance, Shares at Mar. 31, 2020		113,145,900
Redeemable convertible preferred stock, Beginning balance at Mar. 31, 2020		$ 110,995
Beginning balance at Dec. 31, 2020	280,791		$ 13	$ 4	464,597	(183,823)
Beginning balance, Shares at Dec. 31, 2020				43,059,632
Exercise of stock options	$ 166				166
Exercise of stock options, Shares	49,328			49,328
Stock-based compensation	$ 3,845				3,845
Unrealized loss on marketable securities	(107)		(107)
Net loss	(20,971)					(20,971)
Other	(19)				(19)
Ending balance at Mar. 31, 2021	$ 263,705		$ (94)	$ 4	$ 468,589	$ (204,794)
Ending balance, Shares at Mar. 31, 2021				43,108,960