Changes in Accumulated Other Comprehensive Income (Loss) by Component (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (4,133)	$ (3,541)	$ (8,025)	$ (6,890)
Net sales	375,315	364,493	741,975	706,295
Income before income taxes	58,799	53,205	109,777	105,581
Tax benefit	(9,370)	(8,178)	(21,530)	(22,251)
Total reclassifications in the period	49,429	45,027	88,247	83,330
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications in the period	(2,986)	(1,608)	(5,628)	(3,411)
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	(638)	(272)	(947)	(365)
Tax benefit	146	85	215	115
Income from continuing operations	(492)	(187)	(732)	(250)
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	(332)	(164)	414	227
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	(306)	(108)	(533)	(138)
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	(3,300)	(2,410)	(6,417)	(5,051)
Tax benefit	806	989	1,521	1,890
Income from continuing operations	(2,494)	(1,421)	(4,896)	(3,161)
Amortization of prior-service credits, net	(145)	(94)	(291)	(186)
Amortization of actuarial losses	(3,155)	(2,733)	(6,126)	(5,282)
Curtailment gain	0	187	0	187
Settlement gain	$ 0	$ 230	$ 0	$ 230