Real Estate Fund Investments (Income from the Fund and the Co-Investment) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Investment Holdings
New York City real property transfer tax (the Transfer Tax)	$ 0	$ 0	$ 0	$ (13,103)
Income (loss) from real estate fund investments	2,190	(190)	(13,780)	(37,973)
Less (income) loss attributable to noncontrolling interests in consolidated subsidiaries	(5,774)	(3,312)	(34,045)	31,137
Real estate fund investments
Investment Holdings
Net investment income	2,190	3,093	2,382	6,366
Net unrealized loss on held investments	0	(3,283)	(16,162)	(32,796)
Net realized loss on exited investments	0	0	0	(913)
New York City real property transfer tax (the Transfer Tax)	0	0	0	(10,630)
Income (loss) from real estate fund investments	2,190	(190)	(13,780)	(37,973)
Less (income) loss attributable to noncontrolling interests in consolidated subsidiaries	(735)	(558)	(8,427)	34,338
Income (loss) from real estate fund investments attributable to the Operating Partnership	1,455	(748)	(22,207)	(3,635)
Less (income) loss attributable to noncontrolling interests in the Operating Partnership	(95)	46	1,403	224
Income (loss) from real estate fund investments attributable to Vornado	$ 1,360	$ (702)	$ (20,804)	$ (3,411)

The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

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-Topic 230
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-Section 45
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of net income (loss) recognized from investments in real estate partnerships and variable interest entities.

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Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(2))
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Amount after tax of income (loss) attributable to nonredeemable noncontrolling shareholder, unit holder, partner, or other equity holder of a joint venture.

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-Publisher FASB
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-SubTopic 10
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Amount after tax of income (loss) attributable to nonredeemable noncontrolling partner in an operating partnership.

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A tax based on the assessed value of real estate by the local government. The tax is usually based on the value of property (including the land).

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-Publisher FASB
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The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period.

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This element represents income from the real estate fund net of amounts attributable to noncontrolling interests

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This element represents the income (loss) from the Real Estate Fund before allocation to noncontrolling interests

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