SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Affiliates
Collateralized Debt Obligation disclosures
Aggregate secured outstanding debt related to CLOs, held by third parties	$ 193,921,000	$ 296,557,000
Nonaffiliates
Collateralized Debt Obligation disclosures
Aggregate secured outstanding debt related to CLOs, held by third parties	5,058,520,000	5,122,338,000
Collateralized Debt Obligation (CLOs) VIEs
Collateralized Debt Obligation disclosures
Number of Collateralized Loan Obligation (CLOs) VIEs	7	7
Corporate debt investment, par amount	6,300,000,000	6,300,000,000
Estimated fair value of corporate debt instruments	6,100,000,000	6,000,000,000
Collateralized Debt Obligation (CLOs) VIEs | Affiliates
Collateralized Debt Obligation disclosures
Aggregate secured outstanding debt related to CLOs, held by third parties	193,900,000
Collateralized Debt Obligation (CLOs) VIEs | Nonaffiliates
Collateralized Debt Obligation disclosures
Aggregate secured outstanding debt related to CLOs, held by third parties	$ 5,100,000,000