GOODWILL AND INTANGIBLE ASSETS - Summary of Intangible Assets by Intangible Asset Type (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 104,534	$ 97,284
Less accumulated amortization	(45,144)	(38,563)
Intangible assets, net	59,390	58,721
Covenants Not-to-Compete
Finite-Lived Intangible Assets [Line Items]
Intangible assets	26,793	26,162
Less accumulated amortization	(20,150)	(18,968)
Intangible assets, net	6,643	7,194
Client Lists
Finite-Lived Intangible Assets [Line Items]
Intangible assets	77,741	71,122
Less accumulated amortization	(24,994)	(19,595)
Intangible assets, net	$ 52,747	$ 51,527