Accumulated Other Comprehensive Income (Loss) by Component (Reclassified Out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of Products Sold	$ (155,452)	$ (161,964)
Amortization of prior service costs and unrecognized gains	(61,738)	(65,241)
Income tax provision	(2,100)	(1,950)
Net Sales	218,440	223,419
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	429	167
Income tax provision	0	0
Net loss from Continuing Operations	429	167
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	150	(240)
Income tax provision	(31)	11
Net loss from Continuing Operations	119	(229)
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]
Cost of Products Sold	35	(84)
Net Sales	$ 115	$ (156)