Accumulated Other Comprehensive Income (Loss) - Amount Reclassified by Component (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Cost of products sold (excluding depreciation and amortization)	$ (114,018)	$ (85,430)	$ (319,119)	$ (251,552)
Interest expense	(2,099)	(538)	(5,634)	(1,099)
Income before income tax provision	7,005	7,997	20,926	28,308
Tax benefit (expense)	(1,894)	(1,612)	(9,187)	(8,569)
Net income	5,111	6,385	11,739	19,739
Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Net income	(620)	(972)	(1,654)	(2,072)
Defined Benefit Pension Plan Adjustments
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified before tax	(858)	(1,566)	(2,565)	(3,187)
Amounts reclassified, tax benefit	312	586	933	1,185
Amounts reclassified net of tax	(546)	(980)	(1,632)	(2,002)
Prior service credit
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified before tax	3		7
Actuarial losses
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified before tax	(861)	(1,566)	(2,572)	(3,187)
Derivatives
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified net of tax			(22)	(70)
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Income before income tax provision	(118)	30	(40)	(126)
Tax benefit (expense)	44	(22)	18	56
Net income	(74)	8	(22)	(70)
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss) | Foreign exchange contracts
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Cost of products sold (excluding depreciation and amortization)		(153)	143	281
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss) | Natural gas contracts
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Cost of products sold (excluding depreciation and amortization)	(6)	$ 183	21	$ (407)
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss) | Interest rate swap contract
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Interest expense	$ (112)		$ (204)