Income Per Share / Income Per Class A Unit (Narrative) (Details) - shares shares in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share
Weighted average common share equivalents of excluded dilutive securities due to anti-dilutive effect	13,334	12,405
Vornado Realty L.P.
Antidilutive Securities Excluded From Computation Of Earnings Per Share
Weighted average common share equivalents of excluded dilutive securities due to anti-dilutive effect	1,446	130

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration