INCOME TAXES, NET DEFERRED TAX ASSET (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Significant components of net deferred tax asset
Net operating loss carryforward	$ 37,744	$ 34,846
Research and development credit carryforward	1,544	1,390
Stock-based compensation	2,319	2,300
Depreciation and amortization	17	11
Accrued expenses	19	136
Lease liability	360
ROU Asset	(331)
Subtotal	41,672	38,683
Valuation allowance	(41,672)	(38,683)
Net deferred taxes	0	0
Retained earnings	(219,160)	(207,330)
Increase (decrease) in valuation allowance	3,000	2,700
Uncertain tax positions that would affect its effective tax rate	0	$ 0
Amount of significant change in uncertain tax positions over the next 12 months	$ 0