Equity Method Investments in Affiliates - Schedule of Equity Method Investments in Affiliates (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Goodwill	$ 2,648.7	$ 2,689.2	$ 2,661.4
Equity method investments in Affiliates (net)	2,139.5	2,134.4
Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Goodwill	1,262.4	1,264.4
Definite-lived acquired client relationships (net)	479.4	470.1
Indefinite-lived acquired client relationships (net)	119.0	174.4
Undistributed earnings and tangible capital	278.7	225.5
Equity method investments in Affiliates (net)	$ 2,139.5	$ 2,134.4	$ 2,074.8

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

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