FINANCIAL INSTRUMENTS Schedule of Investments Included in Debt Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/ amortized cost	$ 16,448	$ 23,403
Debt instruments, trading, at fair value	7,180	22,473
Corporate debt – U.S.
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/ amortized cost	8,508	21,294
Unrealized gains	0	6,509
Unrealized losses	(7,186)	(5,331)
Debt instruments, trading, at fair value	1,322	22,472
Corporate debt – Non U.S.
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/ amortized cost	2,109	2,109
Unrealized gains	0	0
Unrealized losses	(2,057)	(2,108)
Debt instruments, trading, at fair value	52	1
Sovereign debt – Non U.S.
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/ amortized cost	5,831
Unrealized gains	0
Unrealized losses	(25)
Debt instruments, trading, at fair value	5,806
Debt instruments
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/ amortized cost	16,448	23,403
Unrealized gains	0	6,509
Unrealized losses	$ (9,268)	$ (7,439)