Accumulated Other Comprehensive Income (Loss) by Component (Reclassified Out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of Products Sold	$ (139,650)	$ (170,792)	$ (295,102)	$ (332,756)
Amortization of prior service costs and unrecognized gains	(57,404)	(68,255)	(119,142)	(133,496)
Income tax provision	(750)	(2,075)	(2,850)	(4,025)
Net Sales	(196,300)	(235,858)	(414,740)	(459,277)
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	(439)	176	(10)	343
Income tax provision	0	0	0	0
Net loss from Continuing Operations	(439)	176	(10)	343
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	(591)	(380)	(441)	(620)
Income tax provision	85	24	54	35
Net loss from Continuing Operations	(506)	(356)	(387)	(585)
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	(265)	(544)	(230)	(628)
Net Sales	$ (326)	$ (164)	$ (211)	$ (8)