EQUITY METHOD INVESTMENTS AND INTERESTS IN JOINT VENTURES AND PARTNERSHIPS (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Gain (Loss) on Investments [Line Items]
Net realized and unrealized gains (losses)	$ (13,662)	$ 30,511	$ 103,244	$ (107,521)
Net income (loss) attributable to noncontrolling interests	(259)	(1,281)	1,716	(16,816)
Equity Investments
Gain (Loss) on Investments [Line Items]
Net realized gains (losses)	(4,094)	(4,496)	(4,094)	(3,771)
Net (increase) decrease in unrealized losses	(2,800)	(457)	2,792	(16,449)
Net realized and unrealized gains (losses)	(6,894)	(4,953)	(1,302)	(20,220)
Interests in Joint Ventures and Partnerships
Gain (Loss) on Investments [Line Items]
Net realized gains (losses)	(2,137)	9,736	(36,262)	7,574
Net (increase) decrease in unrealized losses	2,209	(5,346)	66,569	(88,439)
Net realized and unrealized gains (losses)	72	4,390	30,307	(80,865)
Net income (loss) attributable to noncontrolling interests	$ (300)	$ (1,300)	$ 1,700	$ (16,800)