Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (12,915)	$ 3,036	$ (8,053)	$ 8,560
Other comprehensive (loss) income, net of tax:
Interest rate swap	(26)	3	222	31
Foreign currency translation	(1,779)	1,396	(3,060)	3,565
Comprehensive (loss) income	$ (14,720)	$ 4,435	$ (10,891)	$ 12,156