CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (15,361)	$ (14,871)	$ (32,818)	$ (31,337)
Other comprehensive (loss) income
Unrealized (losses) gains on available-for-sale investments, net of taxes	(139)	1,248	(357)	1,011
Comprehensive loss	$ (15,500)	$ (13,623)	$ (33,175)	$ (30,326)