Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Comprehensive Income [Abstract]
Net income	$ 7,337	$ 8,873	$ 7,956	$ 22,646
Pension liability, net of income tax	438	510	1,314	1,529
Cash flow hedging loss, net of income tax	(824)	(361)	(1,904)	(956)
Foreign currency translation adjustment	950	(5,281)	2,667	(14,563)
Comprehensive income	7,901	3,741	10,033	8,656
Pension liability, tax	257	298	771	896
Cash flow hedging gain (loss), tax	$ (483)	$ (212)	$ (1,116)	$ (560)