Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Comprehensive Income
Net income	$ 2,973	$ 2,577	$ (492)	$ 2,298	$ (277)	$ 979	$ 2,214	$ 4,331	$ 6,553	$ (2,229)	$ 9,692	$ 1,610	$ 7,356	$ 7,247	$ 15,626
Other comprehensive (loss) income:
Currency translation adjustment													(796)
Unrealized losses on derivative instruments															(187)
Reclassification adjustment for losses (gains) included in net income														(499)	1,485
Net gain (loss) recognized in other comprehensive income													(796)	(499)	1,298
Tax benefit (expense) related to items of other comprehensive income													275	174	(435)
Other comprehensive income (loss)													(521)	(325)	863
Total comprehensive income													$ 6,835	$ 6,922	$ 16,489