Accumulated Other Comprehensive Income (Loss) (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Amounts reclassified out of accumulated other comprehensive loss
Cost of products sold (excluding depreciation)			$ (366,962)	$ (392,382)	$ (364,384)
Restructuring	(2,200)	(8,000)	129	(10,211)
Income before income tax provision			67,199	37,336	56,390
Tax (expense) or benefit			(21,486)	(14,064)	(17,166)
Net income			45,713	23,272	39,224
Amount Reclassified from Accumulated Other Comprehensive Income
Amounts reclassified out of accumulated other comprehensive loss
Net income			(1,058)
Gains and losses on cash flow hedges | Amount Reclassified from Accumulated Other Comprehensive Income
Amounts reclassified out of accumulated other comprehensive loss
Income before income tax provision			463
Tax (expense) or benefit			(198)
Net income			265
Gains and losses on cash flow hedges | Amount Reclassified from Accumulated Other Comprehensive Income | Foreign Exchange Contracts
Amounts reclassified out of accumulated other comprehensive loss
Cost of products sold (excluding depreciation)			1,018
Gains and losses on cash flow hedges | Amount Reclassified from Accumulated Other Comprehensive Income | Natural gas forward contracts
Amounts reclassified out of accumulated other comprehensive loss
Cost of products sold (excluding depreciation)			(555)
Pension Benefit Adjustments | Amount Reclassified from Accumulated Other Comprehensive Income
Amounts reclassified out of accumulated other comprehensive loss
Prior-service costs			(74)
Actuarial losses			(3,722)
Income before income tax provision			(3,796)
Tax (expense) or benefit			1,441
Net income			(2,355)
Foreign Currency Translation Adjustments | Amount Reclassified from Accumulated Other Comprehensive Income
Amounts reclassified out of accumulated other comprehensive loss
Restructuring			1,032
Income before income tax provision			1,032
Net income			$ 1,032