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Investments previously accounted for at cost that are now being accounted for at Net Asset value

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Investments in Real Estate Ventures, at Fair Value, Additions

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Investments in Real Estate Ventures, at Fair Value, Distributions

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Investments in Real Estate Ventures, at Fair Value, Foreign Currency Translation

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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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Amount of investment in equity method investee and investment in and advance to affiliate.

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Investments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Investments (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Schedule of Equity Method Investments [Line Items]
Investments	$ 895.1		$ 895.1		$ 812.7
Fair Value [Abstract]
Fair value investments at beginning of the period			742.0	$ 740.8
Investments in Real Estate Ventures, at Fair Value, Additions			146.9	72.2
Investments in Real Estate Ventures, at Fair Value, Distributions			(56.9)	(17.3)
Unrealized Gain (Loss) on Investments			(28.2)	(10.7)
Investments in Real Estate Ventures, at Fair Value, Foreign Currency Translation			16.3	2.1
Investments previously accounted at cost that are now being accounted for at Net Asset value	24.6		24.6
Fair value investments at end of the period	844.7	$ 795.5	844.7	795.5
Equity Investments accounted for under the measurement alternative	13.0		13.0
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value [Abstract]
Fair value investments at beginning of the period	293.1	367.8	330.3	367.3
Fair value investments at end of the period	309.0	378.8	309.0	378.8
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Investments [Member]
Fair Value [Abstract]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0.0	$ 0.0	0.0	$ 8.4
Software and Technology Solutions
Schedule of Equity Method Investments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	7.7		7.7
Investments	357.2		357.2		372.8
Fair Value [Abstract]
Asset Impairment Charges			2.2
Investment Management
Schedule of Equity Method Investments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	210.1		210.1
Investments	502.4		502.4		406.1
Other Investments and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
Schedule of Equity Method Investments [Line Items]
Investments	$ 35.5		$ 35.5		$ 33.8