Final Estimated Fair Value of Assets Acquired and Liabilities Assumed at Date of Acquisition (Parenthetical) (Detail) (Maverick Companies, USD $)	12 Months Ended
	Dec. 31, 2012
Customer Relationships
Business Acquisition [Line Items]
Other intangible assets, amortizable	$ 25,300,000
Other intangible assets, amortization period, years	15 years
Noncompete Agreements
Business Acquisition [Line Items]
Other intangible assets, amortizable	3,600,000
Other intangible assets, amortization period, years	5 years
Intellectual Property
Business Acquisition [Line Items]
Other intangible assets, amortizable	380,000
Other intangible assets, amortization period, years	15 years
Trade Names
Business Acquisition [Line Items]
Other intangible assets, indefinite life	$ 170,000