LEASES - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) ft² term	Sep. 30, 2018 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease cost (including related operating costs)	$ 76,000		$ 222,000
Short-term property leases	$ 59,000		$ 188,000
Canada
Lessee, Lease, Description [Line Items]
Office space, square foot | ft²			31,100
Lease term	5 years		5 years
Renewal option | term			1
Renewal term	5 years		5 years
Monthly rent			$ 12,600
Related operating expenses			12,300
Operating lease cost (including related operating costs)	$ 76,000		222,000
Rent expense Under ASC 840		$ 78,000		$ 239,000
Massachusetts
Lessee, Lease, Description [Line Items]
Monthly rent			7,900
Rent expense Under ASC 840		35,000		97,000
Short-term property leases	24,000		75,000
Pennsylvania
Lessee, Lease, Description [Line Items]
Monthly rent			11,000
Rent expense Under ASC 840		$ 36,000		$ 92,000
Short-term property leases	$ 35,000		$ 113,000