INCOME TAXES, NET DEFERRED TAX ASSET (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Significant components of net deferred tax asset
Net operating loss carryforward	$ 31,533	$ 37,245
Research and development credit carryforward	1,173	1,065
Stock-based compensation	2,828	5,235
Depreciation and amortization	71	31
Accrued expenses	357	264
Charitable contributions	27	63
Subtotal	35,989	43,903
Valuation allowance	(35,989)	(43,903)
Increase (decrease) in valuation allowance	(7,914)	9,406
Uncertain tax positions that would affect its effective tax rate	0	$ 0
ASU 2016-09
Significant components of net deferred tax asset
Effect on retained earnings of recording additional deferred tax assets	642
Net deferred tax assets	$ 0