Changes in Accumulated Other Comprehensive Income (Loss) by Component (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (4,054)	$ (3,748)	$ (12,078)	$ (10,638)
Net sales	369,797	357,156	1,111,772	1,063,451
Income before income taxes	52,562	43,681	162,340	149,262
Tax benefit	(13,453)	(8,348)	(34,983)	(30,599)
Total reclassifications in the period	39,109	35,333	127,357	118,663
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications in the period	(2,634)	(2,356)	(8,262)	(5,841)
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	(286)	(214)	(1,233)	(558)
Tax benefit	62	74	277	181
Income from continuing operations	(224)	(140)	(956)	(377)
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	40	(174)	(374)	(380)
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	(326)	(40)	(859)	(178)
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	(3,160)	(3,162)	(9,577)	(8,213)
Tax benefit	750	946	2,271	2,749
Income from continuing operations	(2,410)	(2,216)	(7,306)	(5,464)
Amortization of prior-service credits, net	(146)	(93)	(437)	(279)
Amortization of actuarial losses	(3,014)	(2,771)	(9,140)	(8,053)
Curtailment gain	0	0	0	187
Settlement loss	$ 0	$ (298)	$ 0	$ (68)