Goodwill and Amortizable Intangible Assets - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, Gross Carrying Amount	$ 41,526
Amortizable intangible assets, Accumulated Amortization	18,873
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, Useful Life	2 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, Useful Life	10 years
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, Useful Life	5 years
Amortizable intangible assets, Gross Carrying Amount	2,370
Amortizable intangible assets, Accumulated Amortization	$ 2,187