Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 11,217	$ (5,912)	$ 28,098	$ (413)
Currency translation adjustment, net of tax	(2,463)	2,541	(9,702)	9,271
Comprehensive income (loss)	$ 8,754	$ (3,371)	$ 18,396	$ 8,858