CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 39,122	$ 13,425	$ (8,673)
Other comprehensive loss
Foreign currency translation adjustments, net of taxes	3,008	(1,183)	(999)
Comprehensive income (loss)	$ 42,130	$ 12,242	$ (9,672)