Investments (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Schedule of Equity Method Investments [Line Items]
Investments	$ 873.6		$ 892.9
Fair Value [Abstract]
Fair value investments at beginning of the period	844.0	$ 742.0
Investments in Real Estate Ventures, at Fair Value, Additions	20.5	135.4
Investments in Real Estate Ventures, at Fair Value, Distributions	(43.5)	(34.2)
Unrealized Gain (Loss) on Investments	5.8	(54.3)
Investments in Real Estate Ventures, at Fair Value, Foreign Currency Translation	(5.4)	20.2
Investments previously accounted at cost that are now being accounted for at Net Asset value	0.0	24.6
Fair value investments at end of the period	821.4	833.7
Equity Investments accounted for under the measurement alternative	17.4
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value [Abstract]
Fair value investments at beginning of the period	304.7	330.3
Fair value investments at end of the period	295.6	293.1
Investment Management
Schedule of Equity Method Investments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	305.5
Investments	490.3		505.8
Software and Technology Solutions
Schedule of Equity Method Investments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	5.8
Investments	350.0		353.0
Other Investments and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
Schedule of Equity Method Investments [Line Items]
Investments	$ 33.3		$ 34.1
Software and Technology Solutions
Fair Value [Abstract]
Asset, Impairment Loss		$ 2.2

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