INCOME TAXES (Income Taxes by Jurisdiction) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
U.S. federal
Current	$ 0	$ 0
Deferred	0	0
Total U.S. federal	0	0
U.S. state and local
Current	1	1
Deferred	0	0
Total U.S. state and local	1	1
Provision for (benefit from) for income taxes	(22)	1
Foreign
Current	0	0
Deferred	(23)	0
Total foreign	23	0
Income taxes differ from the amounts computed by applying the U.S. federal income tax rate to pretax income (loss) before income taxes
Expected income tax benefit	(5,191)	(3,291)
State income tax (benefit), net of federal benefit	(1,022)	(693)
Valuation allowance	6,219	4,120
Permanent differences:
Stock options	173	131
Transaction costs	31	0
Research & development credit	(267)	(174)
Adjustment to deferred taxes	(12)	(102)
Foreign rate differential	28	0
Other	19	10
Provision for (benefit from) for income taxes	$ (22)	$ 1