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Redeemable Non-Controlling Interests (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Redeemable Non-controlling Interests
Balance, beginning of period		$ 833.7	[1]	$ 811.9
Changes attributable to consolidated Affiliate sponsored investment products		(69.4)		51.6
Transfers to Other liabilities		(118.6)		(105.4)
Transfers from Non-controlling interests		105.0		44.8		$ 76.8
Changes in redemption value		166.0		30.8
Balance, end of period		916.7	[1]	833.7	[1]	$ 811.9
Affiliate sponsored investment products
Redeemable Non-controlling Interests
Balance, beginning of period	[1]	91.0
Balance, end of period	[1]	$ 21.6		$ 91.0
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
[1] As of December 31, 2018 and 2019, Redeemable non-controlling interests includes consolidated Affiliate sponsored investment products primarily attributable to third-party investors of $91.0 million and $21.6 million, respectively.

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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.

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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
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