FAIR VALUE - Schedule of Fair Value Hierarchy for Financial Assets and Liabilities (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets:
Total	$ 9,629	$ 24,073
Liabilities:
Contingent consideration liability	168	1,038
Total	168	1,038
Money market funds
Assets:
Cash and cash equivalents		11
Commercial paper
Assets:
Cash and cash equivalents		14,028
Agency bond
Assets:
Cash and cash equivalents		1,250
Collegium warrants
Assets:
Investments	9,629	8,784
Level 1
Assets:
Total	0	11
Liabilities:
Contingent consideration liability	0	0
Total	0	0
Level 1 | Money market funds
Assets:
Cash and cash equivalents		11
Level 1 | Commercial paper
Assets:
Cash and cash equivalents		0
Level 1 | Agency bond
Assets:
Cash and cash equivalents		0
Level 1 | Collegium warrants
Assets:
Investments	0	0
Level 2
Assets:
Total	9,629	24,062
Liabilities:
Contingent consideration liability	0	0
Total	0	0
Level 2 | Money market funds
Assets:
Cash and cash equivalents		0
Level 2 | Commercial paper
Assets:
Cash and cash equivalents		14,028
Level 2 | Agency bond
Assets:
Cash and cash equivalents		1,250
Level 2 | Collegium warrants
Assets:
Investments	9,629	8,784
Level 3
Assets:
Total	0	0
Liabilities:
Contingent consideration liability	168	1,038
Total	168	1,038
Level 3 | Money market funds
Assets:
Cash and cash equivalents		0
Level 3 | Commercial paper
Assets:
Cash and cash equivalents		0
Level 3 | Agency bond
Assets:
Cash and cash equivalents		0
Level 3 | Collegium warrants
Assets:
Investments	$ 0	$ 0