Equity Method Investments in Affiliates - Schedule of Equity Method Investments in Affiliates (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Goodwill	$ 2,627.9	$ 2,689.2
Equity method investments in Affiliates (net)	2,046.8	2,134.4
Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Goodwill	1,330.9	1,264.4
Definite-lived acquired client relationships (net)	462.3	470.1
Indefinite-lived acquired client relationships (net)	171.4	174.4
Undistributed earnings and tangible capital	82.2	225.5
Equity method investments in Affiliates (net)	$ 2,046.8	$ 2,134.4

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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