FINANCIAL INSTRUMENTS Schedule of Investments in Equity Securities Trading (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
Equity securities, trading, at fair value	1,195,864	844,001
Equities – listed
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/amortized cost	1,013,956	753,813
Unrealized gains	214,617	115,379
Unrealized losses	(49,737)	(40,706)
Equity securities, trading, at fair value	1,178,836	828,486
Exchange traded funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/amortized cost	15,056	15,056
Unrealized gains	1,972	459
Unrealized losses	0	0
Equity securities, trading, at fair value	17,028	15,515
Total equity securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost/amortized cost	1,029,012	768,869
Unrealized gains	216,589	115,838
Unrealized losses	$ (49,737)	$ (40,706)