Summary of Significant Accounting Policies (Schedule of Accumulated Other Comprehensive Income (loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (179,987)	$ (176,669)
Other comprehensive income (loss) before reclassifications	(28,917)	(14,858)
Amounts reclassified from accumulated other comprehensive income (loss)	11,253	11,540
Other comprehensive income (loss)	(17,664)	(3,318)	$ 6,565
Ending balance	(197,651)	(179,987)	(176,669)
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(96,940)	(86,178)
Other comprehensive income (loss) before reclassifications	(3,723)	(10,762)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Other comprehensive income (loss)	(3,723)	(10,762)
Ending balance	(100,663)	(96,940)	(86,178)
Gain (loss) on derivative financial instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(1,601)	459
Other comprehensive income (loss) before reclassifications	(2,686)	(2,978)
Amounts reclassified from accumulated other comprehensive income (loss)	2,980	918
Other comprehensive income (loss)	294	(2,060)
Ending balance	(1,307)	(1,601)	459
Pension and other post-retirement benefit adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(81,446)	(90,950)
Other comprehensive income (loss) before reclassifications	(22,508)	(1,118)
Amounts reclassified from accumulated other comprehensive income (loss)	8,273	10,622
Other comprehensive income (loss)	(14,235)	9,504
Ending balance	(95,681)	(81,446)	(90,950)
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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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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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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