ORGANIZATION AND NATURE OF OPERATIONS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ (5,119)	$ (4,103)	$ (3,654)	$ (4,580)	$ (9,222)	$ (8,234)
Net cash used in operating activities					(11,290)	$ (9,502)
Cash and cash equivalents	21,570				21,570		$ 7,232
Accumulated deficit	$ (94,202)				$ (94,202)		$ (84,980)