FINANCIAL INSTRUMENTS Schedule of Investments in Equity Securities, Trading (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
Equity securities, trading, at fair value	1,203,672	844,001
Equities – listed
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/ amortized cost	1,014,426	753,813
Unrealized gains	208,350	115,379
Unrealized losses	(19,104)	(40,706)
Equity securities, trading, at fair value	1,203,672	828,486
Exchange traded funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/ amortized cost		15,056
Unrealized gains		459
Unrealized losses		0
Equity securities, trading, at fair value		15,515
Equities – listed
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/ amortized cost	1,014,426	768,869
Unrealized gains	208,350	115,838
Unrealized losses	$ (19,104)	$ (40,706)