STOCK-BASED COMPENSATION (Equity Based Compensation Schedule) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Allocation of stock-based compensation expense
Stock compensation expense	$ 666	$ 552	$ 2,024	$ 1,350
Research and development expenses
Allocation of stock-based compensation expense
Stock compensation expense	324	177	900	515
Research and development expenses | Employees
Allocation of stock-based compensation expense
Stock compensation expense	304	172	839	497
Research and development expenses | Non-employees
Allocation of stock-based compensation expense
Stock compensation expense	20	5	61	18
General and administrative expenses
Allocation of stock-based compensation expense
Stock compensation expense	342	375	1,124	835
General and administrative expenses | Non-employees
Allocation of stock-based compensation expense
Stock compensation expense	28	94	126	130
General and administrative expenses | Employees and directors
Allocation of stock-based compensation expense
Stock compensation expense	$ 314	$ 281	$ 998	$ 705