VARIABLE INTEREST ENTITIES BORROWINGS (Schedule of Debt - Parenthetical) (Details) RSO (USD $)	Sep. 30, 2012	Dec. 31, 2012 RSO [Member]	Dec. 31, 2011 RSO [Member]	Dec. 31, 2012 RSO [Member] RREF CDO 2006-1 Senior Notes [Member]	Dec. 31, 2011 RSO [Member] RREF CDO 2006-1 Senior Notes [Member]	Dec. 31, 2012 RSO [Member] CMBS - Term Repurchase Facilities [Member]	Dec. 31, 2011 RSO [Member] CMBS - Term Repurchase Facilities [Member]	Dec. 31, 2012 RSO [Member] CRE - Term Repurchase Facility [Member]	Dec. 31, 2012 RSO [Member] Mortgages [Member]	Dec. 31, 2011 RSO [Member] Mortgages [Member]	Aug. 01, 2011 RSO [Member] Mortgages [Member]	Dec. 31, 2012 RSO [Member] Whitney CLO I Senior Notes [Member]	Oct. 31, 2012 RSO [Member] Whitney CLO I, Ltd. [Member]	Dec. 31, 2012 RSO [Member] Apidos CLO VIII Senior Notes [Member]	Dec. 31, 2011 RSO [Member] Apidos CLO VIII Senior Notes [Member]	Dec. 31, 2012 RSO [Member] Apidos Cinco CDO Senior Notes [Member]	Dec. 31, 2011 RSO [Member] Apidos Cinco CDO Senior Notes [Member]	Dec. 31, 2012 RSO [Member] Apidos CDO III Senior Notes [Member]	Dec. 31, 2011 RSO [Member] Apidos CDO III Senior Notes [Member]	Dec. 31, 2012 RSO [Member] Apidos CDO I Senior Notes [Member]	Dec. 31, 2011 RSO [Member] Apidos CDO I Senior Notes [Member]	Dec. 31, 2012 RSO [Member] RREF CDO 2007-1 Senior Notes [Member]	Dec. 31, 2011 RSO [Member] RREF CDO 2007-1 Senior Notes [Member]	Dec. 31, 2012 RSO [Member] CMBS [Member] Linked Transactions [Member]	Dec. 31, 2011 RSO [Member] CMBS [Member] Linked Transactions [Member]
Debt Instrument [Line Items]
Principal outstanding				$ 146,400,000	$ 159,100,000	$ 47,500,000	$ 40,900,000	$ 59,100,000	$ 13,600,000	$ 13,600,000	$ 13,600,000	$ 174,100,000		$ 317,600,000	$ 317,600,000	$ 322,000,000	$ 322,000,000	$ 222,000,000	$ 262,500,000	$ 203,200,000	$ 315,900,000	$ 227,400,000	$ 318,600,000
Unamortized debt issuance costs		0	65,000	728,000	1,200,000	23,000	494,000	348,000						4,700,000	5,500,000	1,500,000	2,000,000	659,000	1,300,000	274,000	1,100,000	1,400,000	2,700,000
Unamortized discount	2,600,000											2,500,000		11,900,000	13,800,000
Accrued interest expense		2,918,000	3,260,000			37,000	39,000	79,000
CMBS Linked repurchase agreement																								20,400,000	14,900,000
Purchased equity interests													$ 20,900,000
Ownership interests in variable interest entities (in hundredths)													67.00%