Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Goodwill and Intangible Assets Disclosure [Line Items]
Inflationary growth rate	3.00%
Increase in goodwill related to acquisitions associated with the valuation of Robuschi		$ 0	$ 112,221,000
Amortization of intangible assets		20,100,000	17,100,000
Anticipated amortization of intangible assets in 2013		17,000,000
Anticipated amortization of intangible assets in 2014		17,000,000
Anticipated amortization of intangible assets in 2015		17,000,000
Anticipated amortization of intangible assets in 2016		17,000,000
Anticipated amortization of intangible assets in 2017		17,000,000
Robuschi
Goodwill and Intangible Assets Disclosure [Line Items]
Amortization of intangible assets		$ 3,400,000
Minimum
Goodwill and Intangible Assets Disclosure [Line Items]
Finite-lived intangible assets, useful life		5 years
Maximum
Goodwill and Intangible Assets Disclosure [Line Items]
Finite-lived intangible assets, useful life		25 years