CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (28,614)	$ (34,417)
Other comprehensive income (loss), net of taxes of $0 for all periods:
Foreign currency translation adjustment	944	(1,984)
Total comprehensive loss	$ (27,670)	$ (36,401)