ACCOUNTS PAYABLE AND ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
ACCOUNTS PAYABLE AND ACCRUED EXPENSES
Accounts payable	$ 7,206	$ 6,821
Accrued milestones and supervision payments		5,368
Accrued operating expenses	15,047	16,990
Accrued administrative expenses	1,815	2,767
Accrued interest	5,749	2,045
Total	29,817	$ 33,991
Milestone and supervision installments payments during the period	$ 5,400