FINANCIAL INSTRUMENTS Schedule of Maturity of Debt Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financial Instruments [Abstract]
Debt instruments, trading, within one year, cost	$ 6,106	$ 0
Debt instruments, trading, within one year, fair value	741	0
Debt instruments, trading, from one to five years, cost	1,451	17,803
Debt instruments, trading, from one to five years, fair value	59	19,492
Debt instruments, trading, from five to ten years, cost	2,109	4,649
Debt instruments, trading, from five to ten years, fair value	103	2,327
Debt instruments, trading, more than ten years, cost	951	951
Debt instruments, trading, more than ten years, fair value	834	654
Cost/ amortized cost	10,617	23,403
Debt instruments	$ 1,737	$ 22,473