SIGNIFICANT ACCOUNTING POLICIES - FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Liabilities:
Warrants to purchase Ordinary Shares	$ (11,343)	$ (7,078)
Recurring basis
Assets:
Reverse Repurchase Agreements	30,407	13,001
Money Market Funds	185	6,455
Total financial assets	30,592	19,456
Liabilities:
Warrants to purchase Ordinary Shares	(11,343)	(7,078)
Total financial liabilities	(11,343)	(7,078)
Level 1 | Recurring basis
Assets:
Money Market Funds	185	6,455
Total financial assets	185	6,455
Level 2 | Recurring basis
Assets:
Reverse Repurchase Agreements	30,407	13,001
Total financial assets	30,407	13,001
Level 3 | Recurring basis
Liabilities:
Warrants to purchase Ordinary Shares	(11,343)	(7,078)
Total financial liabilities	$ (11,343)	$ (7,078)