GOODWILL AND OTHER INTANGIBLE ASSETS - Schedule of Goodwill (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) period	Mar. 31, 2017 USD ($)
Goodwill activity
Beginning balance	$ 123,767	$ 96,420
Additions from acquisitions		27,347
Ending balance	123,767	123,767
Contingent liability
Payment of contingent consideration	$ (5,150)	0
Number of annual contingent consideration earn-out periods | period	3
Contingent consideration	$ 9,200	$ 13,700