Investments in Partially Owned Entities (Schedule of Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Schedule Of Equity Method Investments
Carrying amount of investments in partially owned entities	$ 2,682,672	$ 2,610,558
Other liabilities
Schedule Of Equity Method Investments
Carrying amount of investments in partially owned entities	$ (88,577)	(81,229)
Fifth Avenue and Times Square JV
Schedule Of Equity Method Investments
Interest	51.50%
Carrying amount of investments in partially owned entities	$ 2,238,486	2,242,972
Partially owned office buildings/land
Schedule Of Equity Method Investments
Carrying amount of investments in partially owned entities	$ 175,744	118,558
Alexander's
Schedule Of Equity Method Investments
Interest	32.40%
Carrying amount of investments in partially owned entities	$ 72,883	87,510
Other investments
Schedule Of Equity Method Investments
Carrying amount of investments in partially owned entities	$ 195,559	161,518
7 West 34th Street
Schedule Of Equity Method Investments
Interest	53.00%
7 West 34th Street | Other liabilities
Schedule Of Equity Method Investments
Carrying amount of investments in partially owned entities	$ (71,122)	(69,899)
85 Tenth Avenue
Schedule Of Equity Method Investments
Interest	49.90%
85 Tenth Avenue | Other liabilities
Schedule Of Equity Method Investments
Carrying amount of investments in partially owned entities	$ (17,455)	$ (11,330)