DERIVATIVE INSTRUMENTS, CHANGES IN DERIVATIVE WARRANT LIABILITY (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Changes in Derivative Warrant Liability
Balance at beginning of year		$ 1,314
Repurchase of warrants		(40)
Fair value of derivative warrant liability reclassified to additional paid in capital				$ (16,121)
Balance at end of period	$ 4	4	$ 1,314
Warrants
Changes in Derivative Warrant Liability
Balance at beginning of year		1,314	1,907	7,224
Increase in derivative liability prior to warrant exchange		3,029
Reduction in derivative liability due to warrant exchange		(3,537)
Repurchase of warrants	(40)	(40)
Fair value of derivative warrant liability reclassified to additional paid in capital				(16,121)
Increase (decrease) in the fair value of warrants		(762)	(593)	10,804
Balance at end of period	$ 4	$ 4	$ 1,314	$ 1,907