Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (33,917)	$ (65,051)	$ (70,252)
Other comprehensive (loss) income:
Unrealized (loss) gain on available-for-sale debt securities, net	(141)	(50)	67
Comprehensive loss	$ (34,058)	$ (65,101)	$ (70,185)