Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 11,840	$ (15,700)	$ 24,900	$ (2,580)
Other comprehensive income (loss)
Defined benefit plans	160	160	310	310
Foreign currency translation	1,400	1,310	(2,020)	(6,950)
Derivative instruments	(570)	(2,130)	3,330	2,300
Total other comprehensive income (loss)	990	(660)	1,620	(4,340)
Total comprehensive income (loss)	$ 12,830	$ (16,360)	$ 26,520	$ (6,920)