Consolidated Statements of Comprehensive Income (Loss) - 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 loss	$ 65,896	$ (55,627)	$ 135,486	$ (66,951)
Other comprehensive income (loss), net of tax:
Currency translation adjustments	(2,448)	30,008	(14,710)	1,830
Change in unrecognized net periodic pension costs	36	595	157	765
Change in gains and losses on derivative instruments	0	(76)	20,044	(11,473)
Total other comprehensive income (loss), net of tax	(2,412)	30,527	5,491	(8,878)
Comprehensive income (loss)	$ 63,484	$ (25,100)	$ 140,977	$ (75,829)