Financial Instruments - Additional Information (Detail)	6 Months Ended			6 Months Ended				6 Months Ended
	Jun. 30, 2011 USD ($)	Jun. 30, 2011 Accrued liabilities USD ($)	Jun. 30, 2011 Other liabilities USD ($)	Jun. 30, 2011 Interest rate swap agreements USD ($)	Jun. 30, 2011 Interest rate swap agreements EUR (€)	Jun. 30, 2011 Maximum Natural gas swap agreements	Jun. 30, 2011 Minimum Natural gas swap agreements	Jun. 30, 2011 Natural gas swap agreements USD ($) MMBtu	Jun. 30, 2011 Foreign Currency Exchange Rate Risk USD ($)	Jun. 30, 2011 Foreign Currency Exchange Rate Risk EUR (€)
Derivative [Line Items]
Fair value of total outstanding swap agreements	$ 9,200,000	$ 3,800,000	$ 5,400,000
Amount of loss reclassified to earnings from derivatives component of accumulated other comprehensive (loss) income	1,600,000
Estimated amount of loss to be reclassified to earnings from derivatives component of accumulated other comprehensive (loss) income during the next twelve months	(2,000,000)
Percentage of hedged estimated twelve month exposure to fluctuations in natural gas prices								15.00%
Aggregate notional principal amount of outstanding interest rate swap agreements					125,000,000
Net payments under derivative swap agreements				2,600,000				200,000
Aggregate notional principal amount of natural gas swap agreements								479,000
Natural gas fixed prices per MMBtu						4.985	4.198
Euro denominated borrowings designated as net investment hedges										320,000,000
Foreign currency losses of net investment hedges included in accumulated other comprehensive (loss) income, net of deferred tax benefit									30,600,000
Deferred tax benefit, net									$ (12,800,000)