CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (1,310)	$ (10,358)	$ (5,679)	$ (20,783)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(9,621)	(5,566)	(10,311)	(14,111)
Total comprehensive loss	$ (10,931)	$ (15,924)	$ (15,990)	$ (34,894)