Goodwill and Other Intangible Assets (Intangible Assets, Net) (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Goodwill and Other Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	$ 110,319	$ 105,835
Less accumulated amortization	41,268	34,662
Intangible assets subject to amortization, net	69,051	71,173
Customer relationships
Goodwill and Other Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	92,712	88,576
Non-compete agreements
Goodwill and Other Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	13,571	13,223
Trade names
Goodwill and Other Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	1,939	1,939
Other intangible assets
Goodwill and Other Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	$ 2,097	$ 2,097