GOODWILL AND OTHER INTANGIBLE ASSETS - Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 1,018	$ 2,935
Cost of revenue
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	647	1,332
Selling and marketing
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 371	$ 1,603