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Summary of Significant Accounting Policies (Schedule of Accumulated Other Comprehensive Income (loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of Goods and Services Sold	$ 558,967	$ 641,140	$ 679,665
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(197,651)	(179,987)
Other comprehensive income (loss) before reclassifications	(24,263)	(28,917)
Amounts reclassified from accumulated other comprehensive income (loss)	43,510	11,253
Other comprehensive income (loss)	19,247	(17,664)	(3,318)
Ending balance	(178,404)	(197,651)	(179,987)
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(100,663)	(96,940)
Other comprehensive income (loss) before reclassifications	(8,781)	(3,723)
Amounts reclassified from accumulated other comprehensive income (loss)	25,295	0
Other comprehensive income (loss)	16,514	(3,723)
Ending balance	(84,149)	(100,663)	(96,940)
Gain (loss) on derivative financial instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(1,307)	(1,601)
Other comprehensive income (loss) before reclassifications	(3,285)	(2,686)
Amounts reclassified from accumulated other comprehensive income (loss)	6,856	2,980
Other comprehensive income (loss)	3,571	294
Ending balance	2,264	(1,307)	(1,601)
Pension and other post-retirement benefit adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(95,681)	(81,446)
Other comprehensive income (loss) before reclassifications	(12,197)	(22,508)
Amounts reclassified from accumulated other comprehensive income (loss)	11,359	8,273
Other comprehensive income (loss)	(838)	(14,235)
Ending balance	(96,519)	(95,681)	(81,446)
Foreign Currency Forward Contracts [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Gain (loss) on derivative financial instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of Goods and Services Sold	$ (62)	$ (62)	$ 62

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The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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