COMMITMENTS AND CONTINGENCIES - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) ft² renewal_term	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) ft² renewal_term	Sep. 30, 2018 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Lease term	5 years		5 years
Renewal term	3 years		3 years
Number of additional terms | renewal_term	2		2
Area of leased property | ft²	3,038		3,038
Monthly payment, initial year	$ 4,430		$ 4,430
Annual payment percentage increase	3.50%		3.50%
Monthly fees	$ 2,160		$ 2,160
Discount rate	12.00%		12.00%
Expected remaining term	2 years 9 months 18 days		2 years 9 months 18 days
Amortization of operating lease right-of-use asset	$ 17,000		$ 50,000	$ 50,000
Remaining lease term			2 years 1 month 6 days
Lease expense	$ 22,000	$ 22,000	$ 100,000	$ 100,000