Accumulated Other Comprehensive Income (Loss) (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Cost of products sold (excluding depreciation and amortization)	$ (87,218)	$ (87,463)
Income before income tax provision	16,622	14,956
Tax (expense) or benefit	(5,561)	(5,147)
Net income	11,061	9,809
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Net income	(282)	(154)
Defined Benefit Pension Plan Adjustments | Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Income before income tax provision	(743)	(355)
Tax (expense) or benefit	243	130
Net income	(500)	(225)
Prior-service costs | Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Net periodic pension cost	(4)	(18)
Actuarial losses | Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Net periodic pension cost	(739)	(337)
Derivatives | Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Income before income tax provision	320	137
Tax (expense) or benefit	(102)	(66)
Net income	218	71
Derivatives | Amount 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)	444	133
Derivatives | Amount 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)	$ (124)	$ 4