Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net Income (loss)	$ (15,700)	$ 22,020	$ (2,580)	$ 41,110
Other comprehensive income (loss)
Defined benefit plans	160	100	310	200
Foreign currency translation	1,310	(900)	(6,950)	(200)
Derivative instruments	(2,130)	(730)	2,300	1,490
Total other comprehensive income (loss)	(660)	(1,530)	(4,340)	1,490
Total comprehensive income (loss)	$ (16,360)	$ 20,490	$ (6,920)	$ 42,600