Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 22,020	$ 19,600	$ 41,110	$ 43,920
Other comprehensive income
Defined benefit plans	100	2,650	200	2,850
Foreign currency translation	(900)	(6,450)	(200)	(4,090)
Derivative instruments	(730)	5,710	1,490	1,670
Total other comprehensive income (loss)	(1,530)	1,910	1,490	430
Total comprehensive income	$ 20,490	$ 21,510	$ 42,600	$ 44,350