FAIR VALUE MEASUREMENTS - Schedule of reconciliation of opening and closing balances for fair value measurements categorized within Level 3 (Details) - Contingent Consideration Liabilities - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019
Convertible Note Derivative Liability
Beginning balance	$ 0	$ 7,300	$ 7,836	$ 7,689
Payments		(100)		(100)
Accretion expense	0	0	253	247
Valuation adjustment		77		0
Reclassification to other current and long-term liabilities		(7,277)		0
Ending balance	$ 0	$ 0	$ 8,089	$ 7,836