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Redeemable Non-Controlling Interests (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Redeemable Non-controlling Interests
Balance, beginning of period	$ 916.7	$ 833.7
(Decreases) increases attributable to consolidated Affiliate sponsored investment products	13.8	(69.4)
Transfers to Other liabilities	(310.6)	(118.6)
Transfers from (to) Non-controlling interests	(7.8)	105.0	$ 44.8
Changes in redemption value	59.4	166.0
Balance, end of period	671.5	916.7	$ 833.7
Variable Interest Entity, Primary Beneficiary
Redeemable Non-controlling Interests
Balance, beginning of period	21.6
Balance, end of period	$ 35.4	$ 21.6
Minimum
Noncontrolling Interest [Line Items]
Term of conditional right put interest	5 years
Maximum
Noncontrolling Interest [Line Items]
Term of conditional right put interest	15 years

X

- Definition

Noncontrolling Interest, Decrease from Transfers to Noncontrolling Interest Holders

+ References

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- Definition

Noncontrolling Interest, Decrease from Transfers to Other Liabilities

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- Definition

Noncontrolling Interest, Increase (decrease) Attributable to Consolidated Partnerships

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- Definition

Increase (decrease) in redeemable non-controlling interests during the period as a result of a change in the redemption value.

+ References

No definition available.

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- Definition

-- None. No documentation exists for this element. --

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- Definition

Term Of Conditional Right to Put Interest

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph (16)(c)
-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
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-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

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