Investments in Partially Owned Entities (Alexander's Inc.) (Details) - Alexanders Inc $ / shares in Units, $ in Thousands	Sep. 30, 2019 USD ($) $ / shares shares
Equity Method Investments And Income From 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	$ 348.41
Equity method investment fair value	$ 576,294
Excess of investee's fair value over carrying amount	475,066
Excess of investee's carrying amount over equity in net assets	$ 38,882

Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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This item represents the aggregate value of each identified investment accounted for under the equity method of accounting based on the quoted market price for those investments in common stock for which a quoted market price is available.

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Balance held at close of period in number of shares.

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-Publisher FASB
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Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

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Equity Method Investment Fair Value In Excess Of Carrying Amount

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This abstract relates to equity method investments and income from equity method investments

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