CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Non-cash investing and financing activities
Capitalized interest	$ 3,163	$ 27,602	$ 35,170
Accrued capitalized interest	1,300	10,700
Accounts payable and accrued expenses.
Non-cash investing and financing activities
Milestone and supervision payments not yet paid	0	4,900	$ 106,000
Accrued capitalized interest	100	500
Long term debt
Non-cash investing and financing activities
Accrued capitalized interest	$ 1,200	$ 10,200