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Discontinued Operations - Narrative (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Jun. 02, 2021	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Jul. 22, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Tax effect		$ 0.0	$ 176.6	$ 0.0	$ 176.6
Income from discontinued operations, net of tax		$ 0.0	53.4	$ 0.0	75.3
Interests In Landmark
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Redemption of co-investments	$ 31.5
Discontinued Operations, Disposed of by Sale \| Interests In Landmark
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration	690.0
Gain on disposal of discontinued operations			509.2		509.2
Tax effect			176.6		176.6
Discontinued Operations, Disposed of by Sale \| Thompson Siegel & Walmsley, LLC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration						$ 240.0
Discontinued Operations, Held-for-sale \| Landmark Partners, LLC , Carried Interest And Co-Investments
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration	$ 31.5
Income from discontinued operations, net of tax			$ (3.1)		$ 0.0