Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (12,063)	$ (16,918)	$ (26,197)	$ (29,260)
Other comprehensive income (loss):
Foreign currency translation adjustment, net of taxes	271	(2,384)	293	(2,651)
Total comprehensive loss	$ (11,792)	$ (19,302)	$ (25,904)	$ (31,911)