Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pre-tax
Other comprehensive income (loss), pre-tax	$ 115,242	$ 1,772	$ (28,738)
Tax
Total other comprehensive income (loss), tax	(1,422)	108	(4,545)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax	113,820	1,880	(33,283)
Cumulative translation adjustment
Pre-tax
Other comprehensive income (loss) before reclassifications, before tax			(48,114)
Other comprehensive income (loss), pre-tax	107,783	67
Tax
Total other comprehensive income (loss), tax	0	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax	107,783	67
Net gain (loss) arising during the year
Pre-tax
Other comprehensive income (loss) before reclassifications, before tax	(1,438)	(7,432)	9,963
Tax
Other comprehensive income (loss) before reclassifications, tax	53	2,497	(2,375)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Other comprehensive income (loss) before reclassifications, net of tax	(1,385)	(4,935)	7,588
Amortization/recognition of settlement loss
Pre-tax
Reclassifications from AOCI before tax	2,876	2,810	2,938
Tax
Reclassification from AOCI, tax	(106)	(944)	(701)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Reclassification from AOCI, net of tax	2,770	1,866	2,237
Pension and other postretirement adjustments
Pre-tax
Other comprehensive income (loss), pre-tax	1,438	(4,622)	12,901
Tax
Total other comprehensive income (loss), tax	(53)	1,553	(3,076)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax	1,385	(3,069)	9,825
Reclassification adjustments for derivatives
Pre-tax
Other comprehensive income (loss), pre-tax	6,021	6,327	6,475
Tax
Total other comprehensive income (loss), tax	(1,369)	(1,445)	(1,469)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax	$ 4,652	$ 4,882	$ 5,006