GOODWILL AND INTANGIBLE ASSETS - Components of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 97,284	$ 66,113
Less accumulated amortization	(38,563)	(31,346)
Intangible assets, net	58,721	34,767
Intangible amortization expenses	7,218	3,316	$ 2,061
Covenants Not-to-Compete
Finite-Lived Intangible Assets [Line Items]
Intangible assets	26,162	21,750
Less accumulated amortization	(18,968)	(17,584)
Intangible assets, net	7,194	4,166
Client Lists
Finite-Lived Intangible Assets [Line Items]
Intangible assets	71,122	44,363
Less accumulated amortization	(19,595)	(13,762)
Intangible assets, net	$ 51,527	$ 30,601