RSO BORROWINGS (Short-Term Repurchase Agreements) (Details) (Short-Term Repurchase Agreements [Member], RCC Real Estate [Member], USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Deutsche Bank Securities, Inc [Member]
Debt Instrument [Line Items]
Weighted-average interest rate	1.45%	1.46%
Debt instrument term	12 months
Amount at Risk Under Facility [Abstract]
Amount at Risk	$ 9,276,000	$ 2,069,000
Weighted Average Maturity in Days	19 days	7 days
Weighted Average Borrowing Rate	1.45%	1.46%
Wells Fargo Securities, LLC [Member]
Debt Instrument [Line Items]
Principal outstanding	1,700,000	1,900,000
Collateral, number of securities	1	1
Repurchase agreement, fair value of collateral securities	2,800,000	3,100,000
Description of variable rate basis	one-month LIBOR	one-month LIBOR
Basis spread on variable rate (in hundredths)	1.01%	1.25%
Weighted-average interest rate	1.19%	1.46%
Amount at Risk Under Facility [Abstract]
Amount at Risk	10,854,000	1,956,000
Weighted Average Maturity in Days	30 days	28 days
Weighted Average Borrowing Rate	1.19%	1.46%
Linked repurchase agreement borrowings included as derivative instruments	21,500,000	3,500,000
JP Morgan Securities, LLC [Member]
Debt Instrument [Line Items]
Weighted-average interest rate	0.98%	1.01%
Amount at Risk Under Facility [Abstract]
Amount at Risk	9,696,000	2,544,000
Weighted Average Maturity in Days	30 days	11 days
Weighted Average Borrowing Rate	0.98%	1.01%
Linked repurchase agreement borrowings included as derivative instruments	17,800,000	4,700,000
Linked Transactions [Member]
Debt Instrument [Line Items]
Description of variable rate basis	one-month LIBOR
Linked Transactions [Member] | Deutsche Bank Securities, Inc [Member]
Debt Instrument [Line Items]
Principal outstanding	15,100,000	3,100,000
Collateral, number of securities	5
Repurchase agreement, fair value of collateral securities	24,300,000	5,100,000
Description of variable rate basis	one-month LIBOR	one-month LIBOR
Basis spread on variable rate (in hundredths)	1.27%	1.25%
Weighted-average interest rate	1.45%	1.46%
Amount at Risk Under Facility [Abstract]
Weighted Average Borrowing Rate	1.45%	1.46%
Linked Transactions [Member] | Wells Fargo Securities, LLC [Member]
Debt Instrument [Line Items]
Collateral, number of securities	7
Repurchase agreement, fair value of collateral securities	31,100,000	5,700,000
Basis spread on variable rate (in hundredths)	1.02%	1.25%
Weighted-average interest rate	1.20%	1.46%
CMBS Linked repurchase agreement	21,500,000	3,500,000
Amount at Risk Under Facility [Abstract]
Weighted Average Borrowing Rate	1.20%	1.46%
Linked Transactions [Member] | JP Morgan Securities, LLC [Member]
Debt Instrument [Line Items]
Principal outstanding	17,800,000	4,700,000
Collateral, number of securities	4
Repurchase agreement, fair value of collateral securities	$ 26,800,000	$ 7,200,000
Description of variable rate basis	one-month LIBOR	one-month LIBOR
Basis spread on variable rate (in hundredths)	0.79%	0.80%
Weighted-average interest rate	0.98%	1.01%
Amount at Risk Under Facility [Abstract]
Weighted Average Borrowing Rate	0.98%	1.01%