Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Goodwill and Intangible Assets Disclosure [Line Items]
Long lived assets impairment charge	$ 7,000,000
Amortization of intangible assets	41,485,000	35,504,000	25,741,000
Expected amortization expense, 2013	43,700,000
Expected amortization expense, 2014	41,600,000
Expected amortization expense, 2015	39,400,000
Expected amortization expense, 2016	37,500,000
Expected amortization expense, 2017	28,400,000
Trade Name
Goodwill and Intangible Assets Disclosure [Line Items]
Trade name, impairment charge	21,000,000
Trade name, fair value	$ 26,000,000
Trade name, remaining useful life	15 years