Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013
Derivative [Line Items]
Senior note interest rate	5.00%
Fair value of total outstanding swap agreements	$ 11,200,000
Amount reclassified to earnings from change in fair value of derivatives component of accumulated other comprehensive income	(900,000)
Estimated reclassification of change in fair value of derivatives component of accumulated other comprehensive (loss) income to earning during the next twelve months	(3,200,000)
Interest rate swap agreements
Derivative [Line Items]
Aggregate notional principal amount of outstanding interest rate swap agreements	284,600,000
Net payments under derivative swap agreements	1,400,000
Natural gas swap agreements
Derivative [Line Items]
Net payments under derivative swap agreements	100,000
Aggregate notional principal amount of natural gas swap agreements	570,000
Percentage of hedged estimated twelve month exposure to fluctuations in natural gas prices	11.00%
Natural gas swap agreements | Minimum
Derivative [Line Items]
Natural gas fixed prices per MMBtu	3.505
Natural gas swap agreements | Maximum
Derivative [Line Items]
Natural gas fixed prices per MMBtu	3.989
Foreign Currency Exchange Rate Risk
Derivative [Line Items]
Foreign currency gains of net investment hedges included in accumulated other comprehensive (loss) income	9,500,000
Prepaid Expenses and Other Current Assets
Derivative [Line Items]
Fair value of total outstanding swap agreements	200,000
Accrued liabilities
Derivative [Line Items]
Fair value of total outstanding swap agreements	5,700,000
Other liabilities
Derivative [Line Items]
Fair value of total outstanding swap agreements	$ 5,700,000