Unconsolidated Investments - Cash Distributions by Investment Type and Location (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Schedule of Equity Method Investments [Line Items]
Operating	$ 35.2
Investing	46.5	$ 78.7
Multifamily
Schedule of Equity Method Investments [Line Items]
Operating	22.0
Investing	28.3
Commercial
Schedule of Equity Method Investments [Line Items]
Operating	8.2
Investing	0.0
Funds
Schedule of Equity Method Investments [Line Items]
Operating	3.9
Investing	15.2
Residential and Other
Schedule of Equity Method Investments [Line Items]
Operating	1.1
Investing	3.0
Western U.S.
Schedule of Equity Method Investments [Line Items]
Operating	26.9
Investing	35.4
Western U.S. | Multifamily
Schedule of Equity Method Investments [Line Items]
Operating	17.8
Investing	28.3
Western U.S. | Commercial
Schedule of Equity Method Investments [Line Items]
Operating	4.5
Investing	0.0
Western U.S. | Funds
Schedule of Equity Method Investments [Line Items]
Operating	3.9
Investing	4.1
Western U.S. | Residential and Other
Schedule of Equity Method Investments [Line Items]
Operating	0.7
Investing	3.0
Ireland
Schedule of Equity Method Investments [Line Items]
Operating	7.9
Investing	11.1
Ireland | Multifamily
Schedule of Equity Method Investments [Line Items]
Operating	4.2
Investing	0.0
Ireland | Commercial
Schedule of Equity Method Investments [Line Items]
Operating	3.7
Investing	0.0
Ireland | Funds
Schedule of Equity Method Investments [Line Items]
Operating	0.0
Investing	11.1
Ireland | Residential and Other
Schedule of Equity Method Investments [Line Items]
Operating	0.0
Investing	0.0
United Kingdom
Schedule of Equity Method Investments [Line Items]
Operating	0.4
Investing	0.0
United Kingdom | Multifamily
Schedule of Equity Method Investments [Line Items]
Operating	0.0
Investing	0.0
United Kingdom | Commercial
Schedule of Equity Method Investments [Line Items]
Operating	0.0
Investing	0.0
United Kingdom | Funds
Schedule of Equity Method Investments [Line Items]
Operating	0.0
Investing	0.0
United Kingdom | Residential and Other
Schedule of Equity Method Investments [Line Items]
Operating	0.4
Investing	$ 0.0