Goodwill and Intangibles - Schedule of Gross Carrying Amount and Accumulated Amortization (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 204,558	$ 126,814
Accumulated Amortization	66,567	40,497
Net Book Value	137,991	86,317
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	121,015	80,909
Accumulated Amortization	38,651	27,533
Net Book Value	82,364	53,376
Covenants Not-to-Compete [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	11,807	8,602
Accumulated Amortization	4,773	2,466
Net Book Value	7,034	6,136
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	58,136	37,303
Accumulated Amortization	14,076	10,498
Net Book Value	44,060	$ 26,805
Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	13,600
Accumulated Amortization	9,067
Net Book Value	$ 4,533

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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