CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (14,346)	$ (4,081)	$ (36,206)	$ (15,307)
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on investments	(46)	2	(22)	45
Total other comprehensive income (loss)	(46)	2	(22)	45
Comprehensive loss	$ (14,392)	$ (4,079)	$ (36,228)	$ (15,262)