Changes in Accumulated Other Comprehensive Income by Component (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (15,944)	$ (20,629)	$ (16,841)
Net sales	1,124,391	1,491,118	1,495,889
Income before income taxes	101,495	206,844	207,495
Tax benefit	(38,120)	(48,494)	(41,309)
Net income	63,375	158,350	$ 166,186
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	(12,633)	(7,873)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains and Losses on Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(1,332)	(609)
Tax benefit	300	122
Net income	(1,032)	(487)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains and Losses on Cash Flow Hedges | Interest Rate Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	(1,321)	347
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains and Losses on Cash Flow Hedges | Foreign Exchange Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net sales	(11)	(956)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension and Other Postretirement Benefit Items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(15,080)	(9,671)
Tax benefit	3,479	2,285
Net income	(11,601)	(7,386)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of prior-service costs
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(386)	(429)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of actuarial losses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(13,661)	(8,902)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Curtailment loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(484)	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Settlement loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	$ (549)	$ (340)