FAIR VALUE OF FINANCIAL INSTRUMENTS (Details 3) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reconciliation of liabilities measured on Level 3 basis
Transfers from Level 1 into Level 2	$ 0	$ 0	$ 0	$ 0
Transfers from Level 2 into Level 1	0	0	0	0
Collateralized Loan Obligation Secured Notes
Reconciliation of liabilities measured on Level 3 basis
Balance at the beginning of the period				5,501,099,000
Included in earnings				0
Transfers into Level 3				0
Transfers out of level 3				(5,501,099,000)
Purchases				0
Sales				0
Settlements				0
Balance at the end of the period		0		0
Change in unrealized gains or losses for the period included in earnings for liabilities held at the end of the reporting period				0
Corporate Debt Securities
Reconciliation of assets measured on Level 3 basis
Balance at the beginning of the period	150,068,000	307,911,000	194,986,000	317,034,000
Included in earnings	(667,000)	(7,763,000)	(45,549,000)	(11,759,000)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Purchases	0	0	0	0
Sales		(76,366,000)		(80,579,000)
Settlements	(29,000)	2,109,000	(65,000)	1,195,000
Balance at the end of the period	149,372,000	225,891,000	149,372,000	225,891,000
Change in unrealized gains or losses for the period included in earnings for assets held at the end of the reporting period	(667,000)	(11,907,000)	(45,549,000)	(14,418,000)
Residential Mortgage- Backed Securities
Reconciliation of assets measured on Level 3 basis
Balance at the beginning of the period	47,714,000	53,935,000	49,621,000	55,184,000
Included in earnings	748,000	1,239,000	1,080,000	3,015,000
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	(2,662,000)	(2,785,000)	(4,901,000)	(5,810,000)
Balance at the end of the period	45,800,000	52,389,000	45,800,000	52,389,000
Change in unrealized gains or losses for the period included in earnings for assets held at the end of the reporting period	748,000	43,000	1,076,000	196,000
Corporate Loans
Reconciliation of assets measured on Level 3 basis
Balance at the beginning of the period	296,982,000	336,186,000	298,734,000	347,077,000
Included in earnings	(44,943,000)	(2,278,000)	(51,770,000)	(58,048,000)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Purchases	997,000	10,999,000	3,303,000	12,307,000
Sales	(26,685,000)	0	(26,685,000)	(25,511,000)
Settlements	(25,510,000)	(3,860,000)	(22,741,000)	65,222,000
Balance at the end of the period	200,841,000	341,047,000	200,841,000	341,047,000
Change in unrealized gains or losses for the period included in earnings for assets held at the end of the reporting period	(44,943,000)	(2,374,000)	(51,770,000)	(57,161,000)
Equity Investments, at Estimated Fair Value
Reconciliation of assets measured on Level 3 basis
Balance at the beginning of the period	138,563,000	103,319,000	146,648,000	81,719,000
Included in earnings	(17,377,000)	2,213,000	(25,462,000)	(21,114,000)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Purchases	0	0	0	0
Sales	(5,130,000)	0	(5,130,000)	0
Settlements	7,318,000	61,347,000	7,318,000	106,274,000
Balance at the end of the period	123,374,000	166,879,000	123,374,000	166,879,000
Change in unrealized gains or losses for the period included in earnings for assets held at the end of the reporting period	(17,377,000)	2,213,000	(25,462,000)	(20,418,000)
Interests in Joint Ventures and Partnerships
Reconciliation of assets measured on Level 3 basis
Balance at the beginning of the period	748,329,000	719,290,000	888,408,000	718,772,000
Included in earnings	947,000	12,204,000	(79,748,000)	(20,158,000)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Purchases	45,756,000	13,830,000	59,823,000	49,367,000
Sales	0	0	0	0
Settlements	(36,711,000)	(5,727,000)	(110,162,000)	(8,384,000)
Balance at the end of the period	758,321,000	739,597,000	758,321,000	739,597,000
Change in unrealized gains or losses for the period included in earnings for assets held at the end of the reporting period	947,000	12,204,000	(79,748,000)	(19,982,000)
Foreign Exchange Options, Net
Reconciliation of assets measured on Level 3 basis
Balance at the beginning of the period	1,841,000		2,887,000
Included in earnings	(189,000)		(1,235,000)
Transfers into Level 3	0		0
Transfers out of Level 3	0		0
Purchases	0		0
Sales	0		0
Settlements	0		0
Balance at the end of the period	1,652,000		1,652,000
Change in unrealized gains or losses for the period included in earnings for assets held at the end of the reporting period	(189,000)		(1,235,000)
Warrants
Reconciliation of assets measured on Level 3 basis
Balance at the beginning of the period	0	521,000	0	0
Included in earnings	(165,000)	(110,000)	(165,000)	(2,001,000)
Transfers into Level 3		0		0
Transfers out of Level 3		0		0
Purchases		0		0
Sales		0		0
Settlements	2,285,000	0	2,285,000	2,412,000
Balance at the end of the period	2,120,000	411,000	2,120,000	411,000
Change in unrealized gains or losses for the period included in earnings for assets held at the end of the reporting period	(165,000)	(110,000)	(165,000)	(2,001,000)
Options
Reconciliation of assets measured on Level 3 basis
Balance at the beginning of the period	498,000	4,309,000	95,000	5,212,000
Included in earnings	1,614,000	(1,399,000)	2,017,000	(2,302,000)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	0	0	0	0
Balance at the end of the period	2,112,000	2,910,000	2,112,000	2,910,000
Change in unrealized gains or losses for the period included in earnings for assets held at the end of the reporting period	$ 1,614,000	$ (1,399,000)	$ 2,017,000	$ (2,302,000)