LONG-TERM INCENTIVE COMPENSATION - UNRECOGNIZED COMPENSATION (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
Feb. 24, 2016	Dec. 31, 2015
Long-Term Incentive Compensation
Unrecognized compensation		$ 194.0
Weighted-average years		4 years 8 months 12 days
Restricted Stock Awards
Long-Term Incentive Compensation
Unrecognized compensation		$ 87.0
Weighted-average years		3 years 1 month 6 days
Restricted Stock Awards \| Intech Investment Management LLC
Long-Term Incentive Compensation
Unrecognized compensation		$ 1.6
Weighted-average years		3 years
Profits Interest And Other
Long-Term Incentive Compensation
Unrecognized compensation		$ 69.2
Weighted-average years		8 years 1 month 6 days
Mutual Fund Share Awards
Long-Term Incentive Compensation
Unrecognized compensation		$ 37.7
Weighted-average years		2 years 4 months 24 days
Employee stock options
Long-Term Incentive Compensation
Unrecognized compensation		$ 0.1
Weighted-average years		10 months 24 days
Long-term incentive awards granted in 2016
Long-Term Incentive Compensation
Unrecognized compensation	$ 66.2
Vesting period	4 years

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No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
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