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Redeemable Non-Controlling Interests (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Redeemable Noncontrolling Interest [Roll Forward]
Balance, as of December 31, 2018	[1]			$ 833.7
Changes attributable to consolidated Affiliate sponsored investment products				(85.0)
Transfers to Other liabilities				(85.1)
Transfers from Non-controlling interests		$ 31.2	$ 6.6	85.6	$ 30.0
Changes in redemption value				97.9
Balance, as of September 30, 2019		847.1		847.1
Affiliate sponsored investment products
Redeemable Noncontrolling Interest [Roll Forward]
Balance, as of December 31, 2018				91.0
Balance, as of September 30, 2019		$ 6.0		$ 6.0
Minimum
Noncontrolling Interest [Line Items]
Term of conditional right to put interest				5 years
Maximum
Noncontrolling Interest [Line Items]
Term of conditional right to put interest				15 years
[1] As of December 31, 2018 and September 30, 2019, Redeemable non-controlling interests includes consolidated Affiliate sponsored investment products primarily attributable to third-party investors of $91.0 million and $6.0 million, respectively.

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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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