Investments in Partially Owned Entities (Alexander's Inc.) (Details) - Alexander's $ / shares in Units, ft² in Thousands, $ in Thousands	May 03, 2024 USD ($) ft²	May 01, 2024	Apr. 30, 2024	Jun. 30, 2024 USD ($) $ / shares shares
Schedule Of Equity Method Investments
Equity method ownership percentage				32.40%
Equity Method Investee
Schedule Of Equity Method Investments
Ownership common shares, investee (in shares) | shares				1,654,068
Equity method ownership percentage				32.40%
Closing share price (in dollars per share) | $ / shares				$ 224.86
Equity method investment fair value				$ 371,934
Excess of investee's fair value over carrying amount				292,336
Excess of investee's carrying amount over equity in net assets				$ 29,320
Lease fee percentage of rent one to ten years			3.00%
Lease fee percentage of rent eleven to twenty years			2.00%
Lease fee percentage of rent twenty first to thirty years			1.00%
Percentage increase lease fee if broker used			1.00%
Percentage of third-party lease commission		33.00%
Equity Method Investee | Bloomberg L.P
Schedule Of Equity Method Investments
Square footage of real estate property (in sqft) | ft²	947
Lease commission override	$ 5,500
Lease, term	11 years