Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - 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	$ (19,928)	$ (17,248)	$ (42,366)	$ (21,301)
Other comprehensive (loss) income:
Unrealized (loss) gain on available-for-sale debt securities	(3)	(99)	(3)	7
Total comprehensive loss	$ (19,931)	$ (17,347)	$ (42,369)	$ (21,294)