COMMON STOCK, TRANSACTIONS (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended				3 Months Ended			9 Months Ended
	May 30, 2018	Sep. 30, 2018	Jun. 30, 2018	May 31, 2018	Jan. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Common stock disclosures
Proceeds from issuance of common stock and warrants, net of issuance costs										$ 16,511
Fair value adjustment of warrants							$ (1,967)			(12,165)
Warrant reclassified to equity							$ (14,706)			(14,707)
Proceeds from exercise of warrants										55
Number of warrants outstanding						7,673,130			7,673,130
Issuance of common stock to 401(k) plan										6
401(k)
Common stock disclosures
Company contributions to employee 401(k) accounts									$ 45	$ 32
2018 Series A Warrant Exercise price $2.00
Common stock disclosures
Exercise price (in dollars per unit)						$ 2.00			$ 2.00
Number of warrants outstanding						7,586,711			7,586,711
2018 Warrants
Common stock disclosures
Fair value adjustment of warrants		$ 764
Warrant reclassified to equity		$ 14,700
Common Stock
Common stock disclosures
Issuance of common stock in public offerings (in shares)							945			1,652,396
Issuance of common stock to 401(k) plan (in shares)										440
Common Stock | 401(k)
Common stock disclosures
Aggregate number of shares reserved for issuance				4,100
Number of additional shares reserved				4,000
Issuance of common stock to 401(k) plan (in shares)										440
Issuance of common stock to 401(k) plan										$ 6
Underwritten Public Offering, June 2018
Common stock disclosures
Proceeds from issuance of common stock and warrants, net of issuance costs			$ 13,500
Reclassification of derivative warrant liability to additional paid-in capital			$ 286
Derivative loss								$ 12,000
Underwritten Public Offering, June 2018 | 2018 Series A Warrant Exercise price $2.00
Common stock disclosures
Number of shares/warrants comprised in a unit (in shares)			1
Exercise price (in dollars per unit)			$ 2.00					$ 2.00
Warrant expiration term (in years)			5 years					5 years
Underwritten Public Offering, June 2018 | 2018 Series B Warrant Exercise price $.01
Common stock disclosures
Exercise price (in dollars per unit)			$ 0.01					$ 0.01
Warrant expiration term (in years)			20 years					20 years
Proceeds from exercise of warrants							$ 44			55
Number of warrants outstanding						0			0		0
Reclassification of derivative warrant liability to additional paid-in capital							8,700			10,600
Derivative loss							$ 1,200			$ 1,200
Underwritten Public Offering, June 2018 | Common Stock
Common stock disclosures
Number of shares/warrants comprised in a unit (in shares)			1
Number of shares of common stock to be purchased by each warrant			1					1
Underwritten Public Offering, June 2018 | Common Stock And Warrants
Common stock disclosures
Issuance of common stock in public offerings (in shares)			1,378,400
Equity issuance (in price per unit)			$ 2.00					$ 2.00
Pre Funded Units
Common stock disclosures
Issuance of common stock in public offerings (in shares)			6,242,811				4,427,084			5,478,002
Equity issuance (in price per unit)			$ 1.99					$ 1.99
Pre Funded Units | 2018 Series A Warrant Exercise price $2.00
Common stock disclosures
Number of shares/warrants comprised in a unit (in shares)			1
Pre Funded Units | 2018 Series B Warrant Exercise price $.01
Common stock disclosures
Number of shares/warrants comprised in a unit (in shares)			1
Pre Funded Units | Common Stock
Common stock disclosures
Number of shares of common stock to be purchased by each warrant			1					1
Purchase and registration rights agreement | Common Stock
Common stock disclosures
Issuance of common stock in public offerings (in shares)	17,192					0	0			256,804
Aggregate proceeds could be received					$ 15,000
Term					24 months
Deferred offering costs	$ 627
Proceeds from issuance of common stock, net of issuance costs							$ 3,100
Purchase and registration rights agreement | Common Stock | Maximum
Common stock disclosures
Aggregate number of shares reserved for issuance	1,200,000