Consolidated Statements of Comprehensive Income (Loss) - 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		$ 5,061	$ 7,864	$ 20,609	$ 1,803
Other comprehensive income (loss), net of tax
Currency translation adjustment	[1]	99	(251)	(880)	1,953
Comprehensive income		5,160	7,613	19,729	3,756
Net income (loss) attributable to non-controlling interest, net of tax		(10)	75	(22)	180
Total comprehensive income		$ 5,170	$ 7,538	$ 19,751	$ 3,576

[1] No other comprehensive income (loss) is attributable to non-controlling interests.