Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (51,923)	$ (22,987)	$ (35,231)
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on investments	(31)	43	27
Total other comprehensive income (loss)	(31)	43	27
Comprehensive loss	$ (51,954)	$ (22,944)	$ (35,204)