Condensed Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total		Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit	Series A Redeemable Convertible Preferred Stock	Series B Redeemable Convertible Preferred Stock	Series C Redeemable Convertible Preferred Stock
Beginning balance (in shares) at Dec. 31, 2019							56,000,000	49,501,221	26,360,745
Beginning balance at Dec. 31, 2019							$ 62,468	$ 75,860	$ 47,947
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series C redeemable preferred stock (in shares)									28,527,313
Issuance of Series C redeemable preferred stock, net of issuance costs									$ 52,038
Ending balance (in shares) at Mar. 31, 2020							56,000,000	49,501,221	54,888,058
Ending balance at Mar. 31, 2020							$ 62,468	$ 75,860	$ 99,985
Beginning balance (in shares) at Dec. 31, 2019			1,846,024
Beginning balance at Dec. 31, 2019	$ (76,295)		$ 1	$ 0	$ (1)	$ (76,295)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock awards (in shares)			52,093
Vesting of restricted stock awards	4			4
Option exercises (in shares)			8,232
Option exercises	26			26
Stock-based compensation expense	425			425
Net unrealized gain on short-term investments	60				60
Net income (loss)	11,029					11,029
Ending balance (in shares) at Mar. 31, 2020			1,906,349
Ending balance at Mar. 31, 2020	$ (64,751)		$ 1	455	59	(65,266)
Beginning balance (in shares) at Dec. 31, 2020							0	0	0
Beginning balance at Dec. 31, 2020							$ 0	$ 0	$ 0
Ending balance (in shares) at Mar. 31, 2021							0	0	0
Ending balance at Mar. 31, 2021							$ 0	$ 0	$ 0
Beginning balance (in shares) at Dec. 31, 2020	35,552,795		35,552,795
Beginning balance at Dec. 31, 2020	$ 283,061	[1]	$ 3	400,918	(32)	(117,828)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock awards (in shares)			30,277
Vesting of restricted stock awards	2			2
Option exercises (in shares)			165,264
Option exercises	1,370			1,370
Stock-based compensation expense	2,578			2,578
Net unrealized gain on short-term investments	14				14
Net income (loss)	$ (22,856)					(22,856)
Ending balance (in shares) at Mar. 31, 2021	35,748,336		35,748,336
Ending balance at Mar. 31, 2021	$ 264,169		$ 3	$ 404,868	$ (18)	$ (140,684)

[1] The condensed balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date.