CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 12,785	$ 11,186	$ 32,767	$ 40,940
Other comprehensive income:
Foreign currency translation adjustments	(1,056)	(1,318)	(2,324)	(7,305)
Pension liability adjustment, net of tax	142	136	427	410
Comprehensive income	$ 11,871	$ 10,004	$ 30,870	$ 34,045