GOODWILL AND OTHER INTANGIBLE ASSETS - Amortization of Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 2,935	$ 2,837
Cost of revenue
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	1,332	1,232
Selling and marketing
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 1,603	$ 1,605