Accumulated Other Comprehensive Income (Loss) - Amount Reclassified by Component (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Cost of products sold (excluding depreciation and amortization)	$ (106,286)	$ (87,663)	$ (205,101)	$ (166,122)
Interest expense	(2,021)	(228)	(3,535)	(561)
Income before income tax provision	9,031	11,952	13,921	20,311
Tax (expense) or benefit	(3,178)	(4,056)	(7,293)	(6,957)
Net income	5,853	7,896	6,628	13,354
Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Net income	(550)	(563)	(1,034)	(1,100)
Defined Benefit Pension Plan Adjustments
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified before tax	(856)	(779)	(1,707)	(1,621)
Amounts reclassified, tax (expense) or benefit	312	298	621	599
Amounts reclassified net of tax	(544)	(481)	(1,086)	(1,022)
Prior-service credit
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified before tax	2		4
Actuarial losses
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified before tax	(858)	(779)	(1,711)	(1,621)
Derivatives
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified net of tax			52	(78)
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Income before income tax provision	(11)	(162)	78	(156)
Tax (expense) or benefit	5	80	(26)	78
Net income	(6)	(82)	52	(78)
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)	66	153	143	434
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)	15	$ (315)	27	$ (590)
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss) | Interest rate swap contract
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Interest expense	$ (92)		$ (92)