FINANCIAL INSTRUMENTS Schedule of Investments Included in Debt Instruments (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/amortized cost	$ 10,617	$ 23,403
Debt instruments	1,737	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	(6,874)	(5,331)
Debt instruments	1,634	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	(2,006)	(2,108)
Debt instruments	103	1
Total debt instruments
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/amortized cost	10,617	23,403
Unrealized gains	0	6,509
Unrealized losses	$ (8,880)	$ (7,439)