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	$ (18,695)	$ (18,987)	$ (35,595)	$ (45,681)
Other comprehensive loss:
Unrealized (loss) gain on available-for-sale securities	(11)	1	(11)	(1)
Comprehensive loss	$ (18,706)	$ (18,986)	$ (35,606)	$ (45,682)