Goodwill and Intangibles - Schedule of Gross Carrying Amount, Accumulated Amortization and Net Book Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 117,840	$ 96,448
Accumulated Amortization	37,417	29,230
Net Book Value	80,423	67,218
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	75,261	62,399
Accumulated Amortization	25,562	20,231
Net Book Value	49,699	42,168
Covenants Not-to-compete [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,143	5,729
Accumulated Amortization	2,003	847
Net Book Value	6,140	4,882
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	34,436	28,320
Accumulated Amortization	9,852	8,152
Net Book Value	$ 24,584	$ 20,168