Investments in Partially Owned Entities (Alexander's Inc.) (Details) - Alexander's $ / shares in Units, $ in Thousands	Mar. 31, 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	$ 217.14
Equity method investment fair value	$ 359,164
Excess of investee's fair value over carrying amount	273,904
Excess of investee's carrying amount over equity in net assets	$ 29,494