Investments in Partially Owned Entities (Schedule of Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Mortgage loans on real estate, face amount of mortgages	$ 303,000
Investments in partially owned entities
Schedule of Equity Method Investments [Line Items]
Equity method investment pro rata share debt of partially owned entities	2,477,701	$ 2,654,701
7 West 34th Street
Schedule of Equity Method Investments [Line Items]
Mortgage loans on real estate, face amount of mortgages	$ 300,000
Partially owned office buildings
Schedule of Equity Method Investments [Line Items]
Weighted average interest rate	4.84%
Equity method investment debt of partially owned entities	$ 3,146,918	3,275,098
Alexander's
Schedule of Equity Method Investments [Line Items]
Equity method ownership percentage	32.40%
Weighted average interest rate	3.94%
Equity method investment debt of partially owned entities	$ 996,544	1,096,544
Fifth Avenue and Times Square JV
Schedule of Equity Method Investments [Line Items]
Equity method ownership percentage	51.50%
Weighted average interest rate	6.93%
Equity method investment debt of partially owned entities	$ 753,194	855,476
Other
Schedule of Equity Method Investments [Line Items]
Weighted average interest rate	5.05%
Equity method investment debt of partially owned entities	$ 1,311,662	$ 1,365,954