VARIABLE INTEREST ENTITIES - FINANCING RECEIVABLES (Impaired Loans) (Details) RSO (RSO [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Net Balance	$ 169,612,000	$ 204,005,000
Unpaid Principal Balance	169,612,000	203,958,000
Specific Allowance	(570,000)	(7,193,000)
Average Investment in Impaired Loans	170,599,000	186,315,000
Interest Income Recognized	15,686,000	11,676,000
Whole Loans [Member]
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded balance	128,108,000	130,759,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	25,572,000
Net Balance	128,108,000	156,331,000
Loans without a specific valuation allowance, Unpaid Principal Balance	128,108,000	130,759,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	25,572,000
Unpaid Principal Balance	128,108,000	156,331,000
Specific Allowance	0	(4,572,000)
Loans without a specific valuation allowance, Average Investment in Impaired Loans	130,445,000	123,495,000
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	24,748,000
Average Investment in Impaired Loans	130,445,000	148,243,000
Loans without a specific valuation allowance, Interest Income Recognized	12,679,000	8,439,000
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	1,622,000
Interest Income Recognized	12,679,000	10,061,000
B Notes [Member]
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded balance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0
Net Balance	0	0
Loans without a specific valuation allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0
Unpaid Principal Balance	0	0
Specific Allowance	0	0
Loans without a specific valuation allowance, Average Investment in Impaired Loans	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Average Investment in Impaired Loans	0	0
Loans without a specific valuation allowance, Interest Income Recognized	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Interest Income Recognized	0	0
Mezzanine Loans [Member]
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded balance	38,072,000	38,072,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0
Net Balance	38,072,000	38,072,000
Loans without a specific valuation allowance, Unpaid Principal Balance	38,072,000	38,072,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0
Unpaid Principal Balance	38,072,000	38,072,000
Specific Allowance	0	0
Loans without a specific valuation allowance, Average Investment in Impaired Loans	38,072,000	38,072,000
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Average Investment in Impaired Loans	38,072,000	38,072,000
Loans without a specific valuation allowance, Interest Income Recognized	2,859,000	1,615,000
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Interest Income Recognized	2,859,000	1,615,000
Bank Loans [Member]
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded balance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	1,350,000	3,554,000
Net Balance	1,350,000	3,554,000
Loans without a specific valuation allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	1,350,000	3,554,000
Unpaid Principal Balance	1,350,000	3,554,000
Specific Allowance	(570,000)	(2,621,000)
Loans without a specific valuation allowance, Average Investment in Impaired Loans	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Average Investment in Impaired Loans	0	0
Loans without a specific valuation allowance, Interest Income Recognized	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Interest Income Recognized	0	0
Middle-market Loans [Member]
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded balance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0
Net Balance	0	0
Loans without a specific valuation allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0
Unpaid Principal Balance	0	0
Specific Allowance	0	0
Loans without a specific valuation allowance, Average Investment in Impaired Loans	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Average Investment in Impaired Loans	0	0
Loans without a specific valuation allowance, Interest Income Recognized	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Interest Income Recognized	0	0
Residential Mortgage Loans [Member]
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded balance	2,082,000	315,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0
Net Balance	2,082,000	315,000
Loans without a specific valuation allowance, Unpaid Principal Balance	2,082,000	268,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0
Unpaid Principal Balance	2,082,000	268,000
Specific Allowance	0	0
Loans without a specific valuation allowance, Average Investment in Impaired Loans	2,082,000	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Average Investment in Impaired Loans	2,082,000	0
Loans without a specific valuation allowance, Interest Income Recognized	148,000	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Interest Income Recognized	148,000	0
Loans Receivable - Related Party [Member]
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded balance	0	5,733,000
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0
Net Balance	0	5,733,000
Loans without a specific valuation allowance, Unpaid Principal Balance	0	5,733,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0
Unpaid Principal Balance	0	5,733,000
Specific Allowance	0	0
Loans without a specific valuation allowance, Average Investment in Impaired Loans	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Average Investment in Impaired Loans	0	0
Loans without a specific valuation allowance, Interest Income Recognized	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Interest Income Recognized	$ 0	$ 0