INTANGIBLE ASSETS - Summary of Intangible Assets by Intangible Asset Type (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 66,113	$ 66,113
Less accumulated amortization	(32,747)	(31,346)
Intangible assets, net	33,366	34,767
Covenants Not-to-Compete
Finite-Lived Intangible Assets [Line Items]
Intangible assets	21,750	21,750
Less accumulated amortization	(17,820)	(17,584)
Intangible assets, net	3,930	4,166
Client Lists
Finite-Lived Intangible Assets [Line Items]
Intangible assets	44,363	44,363
Less accumulated amortization	(14,927)	(13,762)
Intangible assets, net	$ 29,436	$ 30,601

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

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