Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pre-tax
Other comprehensive income (loss), pre,tax	$ 1,772	$ (28,738)	$ 114,352
Tax
Total other comprehensive income (loss), tax	108	(4,545)	(2,206)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax	1,880	(33,283)	112,146
Foreign currency translation adjustments
Pre-tax
Other comprehensive income (loss) before reclassifications, before tax			110,421
Reclassifications from AOCI before tax			2,749
Other comprehensive income (loss), pre,tax	67	(48,114)
Tax
Total other comprehensive income (loss), tax	0	0	(3,932)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax	67	(48,114)	109,238
Net gain (loss) arising during the year
Pre-tax
Other comprehensive income (loss) before reclassifications, before tax	(7,432)	9,963	(5,355)
Tax
Other comprehensive income (loss) before reclassifications, tax	2,497	(2,375)	828
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Other comprehensive income (loss) before reclassifications, net of tax	(4,935)	7,588	(4,527)
Amortization/recognition of settlement loss
Pre-tax
Reclassifications from AOCI before tax	2,810	2,938	3,814
Tax
Reclassification from AOCI, tax	(944)	(701)	(589)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Reclassification from AOCI, net of tax	1,866	2,237	3,225
Pension and other postretirement adjustments
Pre-tax
Other comprehensive income (loss), pre,tax	(4,622)	12,901	(1,541)
Tax
Total other comprehensive income (loss), tax	1,553	(3,076)	239
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax	(3,069)	9,825	(1,302)
Reclassification adjustments for derivatives
Pre-tax
Other comprehensive income (loss), pre,tax	6,327	6,475	6,655
Tax
Total other comprehensive income (loss), tax	(1,445)	(1,469)	(2,445)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax	$ 4,882	$ 5,006	$ 4,210