GOODWILL AND INTANGIBLE ASSETS - Summary of Intangible Assets by Intangible Asset Type (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 56,479	$ 36,179
Less accumulated amortization	(29,878)	(28,030)
Intangible assets, net	26,601	8,149
Covenants Not-to-Compete
Finite-Lived Intangible Assets [Line Items]
Intangible assets	19,192	18,092
Less accumulated amortization	(17,371)	(16,851)
Intangible assets, net	1,821	1,241
Client Lists
Finite-Lived Intangible Assets [Line Items]
Intangible assets	37,287	18,087
Less accumulated amortization	(12,507)	(11,179)
Intangible assets, net	$ 24,780	$ 6,908

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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