CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (17,534)	$ (4,158)	$ (21,860)	$ (11,226)
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on investments	(47)	27	24	43
Total other comprehensive income (loss)	(47)	27	24	43
Comprehensive loss	$ (17,581)	$ (4,131)	$ (21,836)	$ (11,183)