CONDENSED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (26,697)	$ (19,651)	$ (84,095)	$ (51,830)
Net unrealized gain (loss) on marketable securities, net of taxes	13	(19)	(62)	38
Comprehensive loss	$ (26,684)	$ (19,670)	$ (84,157)	$ (51,792)