Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 19,590	$ (100,870)	$ 44,490	$ (103,450)
Other comprehensive income (loss)
Defined benefit plans	160	160	470	470
Foreign currency translation	(4,550)	5,740	(6,570)	(1,210)
Derivative instruments	3,880	(4,580)	7,210	(2,280)
Total other comprehensive income (loss)	(510)	1,320	1,110	(3,020)
Total comprehensive income (loss)	$ 19,080	$ (99,550)	$ 45,600	$ (106,470)