LOAN PAYABLE, ACTIVITY (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended		3 Months Ended		6 Months Ended
	May 01, 2015	May 31, 2018	Oct. 31, 2012	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Loans Payable
Outstanding loan payable								$ 100
Number of warrants outstanding				7,673,130		7,673,130
2012 Warrant Exercise price $166.00
Loans Payable
Number of warrants outstanding				243		243
Exercise price of warrant (in dollars per share)				$ 166.00		$ 166.00
Equipment Line of Credit
Loans Payable
Amortization of warrant				$ 0	$ 12
Interest expense						$ 1	$ 26
Interest Expense, Debt [Abstract]
Interest expense				0	12
MassDev
Loans Payable
Line of credit, maximum			$ 2,000
Line of credit for working capital purpose			$ 200
Fixed interest rate (as a percent)			6.50%
Period for interest-only payments			30 months
Period for charging equal installments of interest and principal			54 months
Maturity date			Mar. 01, 2019
Commencement date of monthly installments	May 01, 2015
Amount of monthly payment	$ 41
Repayment of principal		$ 300				100
Outstanding loan payable				0		0
MassDev | 2012 Warrant Exercise price $166.00
Loans Payable
Amortization of warrant				0	1		2
Warrant period			7 years
Exercise price of warrant (in dollars per share)			$ 166.00
Fair value of warrants			$ 32
Interest Expense, Debt [Abstract]
Interest expense				$ 0	$ 1		$ 2
MassDev | 2012 Warrant Exercise price $166.00 | Interest Expense
Loans Payable
Amortization of warrant						1
Interest Expense, Debt [Abstract]
Interest expense						$ 1
MassDev | 2012 Warrant Exercise price $166.00 | Common Stock
Loans Payable
Number of shares into which a warrant may be converted			362
Number of warrants outstanding				243		243