COMMITMENTS AND CONTINGENCIES - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
	Mar. 15, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Schedule of Asset Acquisition [Line Items]
Commitment to pay minimum processing fees under agreements		$ 14,000
Asset acquisition, contingent consideration	$ 2,100
Asset acquisition, intangible assets	15,200
Proceeds from lines of credit		3,500	$ 10,000
Contingent cash payments for asset acquisitions	6,400
Term Loan | Syndicate of Lenders | Line of Credit
Schedule of Asset Acquisition [Line Items]
Proceeds from lines of credit	5,000
Revolving Credit Facility
Schedule of Asset Acquisition [Line Items]
Proceeds from lines of credit	$ 10,000
Service Agreements
Schedule of Asset Acquisition [Line Items]
Asset acquisition, contingent consideration		$ 2,100		$ 1,100