VARIABLE INTEREST ENTITIES LOANS HELD FOR INVESTMENT (Weighted Average Life of Commercial Real Estate Loans, at Amortized Cost) (Details) RSO (RSO [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Middle-market Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less than one year	$ 0	$ 0
Loans held for investment, amortized cost	294,793	250,113
Greater than one year and less than five years	158,183	132,353
Five years or greater	136,610	117,760
Bank Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less than one year	1,625	7,829
Loans held for investment, amortized cost	298,209	330,930
Greater than one year and less than five years	282,658	274,332
Five years or greater	13,926	48,769
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2014	0	0
2015	60,448	60,473
2016 and Thereafter	1,385,436	1,286,557
Loans held for investment, amortized cost	1,445,884	1,347,030
Commercial Real Estate Loans [Member] | Whole Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2014	0	0
2015	27,678	27,665
2016 and Thereafter	1,334,704	1,235,927
Loans held for investment, amortized cost	1,362,382	1,263,592
Commercial Real Estate Loans [Member] | Mezzanine Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2014	0	0
2015	16,739	16,736
2016 and Thereafter	50,732	50,630
Loans held for investment, amortized cost	67,471	67,366
Commercial Real Estate Loans [Member] | B Notes [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
2014	0	0
2015	16,031	16,072
2016 and Thereafter	0	0
Loans held for investment, amortized cost	$ 16,031	$ 16,072