FAIR VALUE MEASUREMENTS - Warrants Liability (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Reclassification of derivative liability to equity upon exercise of warrants	$ (200)
Warrants liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	38,810
Reclassification of derivative liability to equity upon exercise of warrants	(173)
Change in estimated fair value of liability classified warrants	(5,277)
Ending Balance	$ 33,360