Investments In Unconsolidated Subsidiaries - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Revenue	$ 31,949.0	$ 30,828.0	$ 27,746.0
Additional investment	$ 0.0	101.0	0.0
Ownership Percentage \| Minimum
Schedule of Equity Method Investments [Line Items]
Equity method investments in unconsolidated subsidiaries, variations in ownership percentage	1.00%
Ownership Percentage \| Maximum
Schedule of Equity Method Investments [Line Items]
Equity method investments in unconsolidated subsidiaries, variations in ownership percentage	50.00%
Investment management \| Real Estate Investments \| Related Party
Schedule of Equity Method Investments [Line Items]
Revenue	$ 278.8	268.9	213.5
Related party receivable	83.2	73.2
Development and Construction Management Revenues \| Related Party
Schedule of Equity Method Investments [Line Items]
Revenue	165.0	147.8	$ 104.3
Related party receivable	$ 30.4	$ 21.1

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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