DERIVATIVE INSTRUMENTS, CHANGES IN DERIVATIVE WARRANT LIABILITY (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Changes in Derivative Warrant Liability
Balance at beginning of year	$ 4	$ 1,314
Issuance of new warrants	13,172
Reduction in derivative liability due to exercise of warrants	(10,620)
Reclassification of fair value of derivative liabilities to equity on amendment of warrant agreements	(14,707)
Increase in derivative liability prior to warrant exchange		3,029
Reduction in derivative liability due to warrant exchange		(3,537)
Repurchase of warrants	(14)	(40)
Increase (decrease) in the fair value of warrants	$ 12,165	(762)
Balance at end of period		$ 4