CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 27,523	$ 20,121	$ 23,802
Other comprehensive income (loss):
Cash flow hedges	901	4,784	(571)
Less income tax benefit (expense)	(350)	(1,861)	222
Foreign currency translation adjustment	3,117	878	(3,037)
Less income tax benefit (expense)	(252)	(196)	311
Total other comprehensive income (loss)	3,416	3,605	(3,075)
Total comprehensive income	$ 30,939	$ 23,726	$ 20,727