Accumulated Other Comprehensive Income (Loss) by Component (Reclassified Out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net Sales	$ 237,060	$ 231,723
Cost of Products Sold	(170,543)	(166,578)
Amortization of prior service costs and unrecognized gains	(71,264)	(72,513)
Income tax provision	(2,350)	(2,600)
Accumulated Defined Benefit Plans Adjustment [Member] \| Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service costs and unrecognized gains	(129)	210
Income tax provision	0	0
Net loss from Continuing Operations	(129)	210
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] \| Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (Loss) from Continuing Operations before Income Taxes	276	(323)
Income tax provision	(28)	24
Net loss from Continuing Operations	248	(299)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] \| Reclassification out of Accumulated Other Comprehensive Income \| Foreign currency forward contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net Sales	(25)	(68)
Cost of Products Sold	$ 251	$ (391)

The aggregate cost of goods produced and sold and services rendered during the reporting period.

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Amount after tax of income (loss) from continuing operations attributable to the parent.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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