BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013 Investment	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013 Investment	Dec. 31, 2012	Dec. 31, 2011
Variable Interest Entity [Line Items]
Negative fund performance that would cause reversal of performance fees									$ 6.1
Accrued performance fees	17.5				8.6				17.5	8.6	4.2
Interest income from loan pool participations and notes receivable	3.3	4.0	3.3	2.9	2.1	3.7	2.9	0.5	13.5	9.2	8.0
Number of investments in joint ventures classified as investment companies	3								3
Fair value option, number of investments	2								2
Operating distributions from joint ventures									56.1	40.4	13.0
Net cash provided by (used in) operating activities									31.3	16.7	3.4
Investing distributions from joint ventures									81.5	38.7	23.3
Net Cash Provided by (Used in) Investing Activities									(348.8)	(399.7)	(207.5)
Guarantees, maximum exposure	51.1				55.5				51.1	55.5
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Variable interest entity, number of investments									5
UNITED KINGDOM
Variable Interest Entity [Line Items]
Operating distributions from joint ventures									13.2
Investing distributions from joint ventures									4.7
UK Loan Pool 1 [Member] | November 2011 [Member] | UNITED KINGDOM
Variable Interest Entity [Line Items]
Interest income from loan pool participations and notes receivable									23.2
Scenario, Previously Reported [Member]
Variable Interest Entity [Line Items]
Operating distributions from joint ventures										30.4	3.6
Net cash provided by (used in) operating activities										6.8	(6.0)
Investing distributions from joint ventures										48.7	32.7
Net Cash Provided by (Used in) Investing Activities										$ (389.7)	$ (198.1)