FAIR VALUE - Schedule of Fair Value Hierarchy for Financial Assets and Liabilities (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets:
Total	$ 6,483	$ 9,629
Collegium warrants
Assets:
Investments, net	6,483	9,629
Level 1
Assets:
Total	0	0
Level 1 | Collegium warrants
Assets:
Investments, net	0	0
Level 2
Assets:
Total	6,483	9,629
Level 2 | Collegium warrants
Assets:
Investments, net	6,483	9,629
Level 3
Assets:
Total	0	0
Level 3 | Collegium warrants
Assets:
Investments, net	$ 0	$ 0