Income Per Share / Income Per Class A Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Numerator:
Income from continuing operations, net of income attributable to noncontrolling interests	$ 32,050	$ 69,037	$ 196,684	$ 337,339
(Loss) income from discontinued operations, net of income attributable to noncontrolling interests	(44,948)	23,543	(13,600)	(97,732)
Net (loss) income attributable to Vornado / Vornado Realty L.P.	(12,898)	92,580	183,084	239,607
Preferred share dividends / unit distributions	(16,128)	(19,047)	(48,386)	(59,774)
Preferred share / unit issuance costs (Series J redemption)	0	(7,408)	0	(7,408)
NET (LOSS) INCOME attributable to common shareholders & Class A unitholders	(29,026)	66,125	134,698	172,425
Earnings allocated to unvested participating securities	(9)	(13)	(37)	(43)
Numerator for basic (loss) income per share / per Class A unit	(29,035)	66,112	134,661	172,382
Earnings allocated to Out-Performance Plan units	0	0	195	96
Numerator for diluted (loss) income per share / per Class A unit	$ (29,035)	$ 66,112	$ 134,856	$ 172,478
Denominator:
Denominator for basic income (loss) per share - weighted average shares (in shares)	189,593	188,901	189,401	188,778
Vornado employee stock options and restricted share / unit awards (in shares)	1,254	1,147	1,553	1,067
Out-Performance Plan units	0	0	303	241
Denominator for diluted (loss) income per share - weighted average shares and assumed conversions (in shares)	190,847	190,048	191,257	190,086
(LOSS) INCOME PER COMMON SHARE – BASIC:
Income from continuing operations, net (in dollars per share)	$ 0.09	$ 0.23	$ 0.78	$ 1.43
(Loss) income from discontinued operations, net (in dollars per share)	(0.24)	0.12	(0.07)	(0.52)
Net (loss) income per common share (in dollars per share)	(0.15)	0.35	0.71	0.91
(LOSS) INCOME PER COMMON SHARE – DILUTED:
Income from continuing operations, net (in dollars per share)	0.09	0.23	0.78	1.42
(Loss) income from discontinued operations, net (in dollars per share)	(0.24)	0.12	(0.07)	(0.51)
Net (loss) income per common share (in dollars per share)	$ (0.15)	$ 0.35	$ 0.71	$ 0.91
Vornado Realty L.P.
Numerator:
Income from continuing operations, net of income attributable to noncontrolling interests	$ 33,154	$ 71,866	$ 206,642	$ 355,221
(Loss) income from discontinued operations, net of income attributable to noncontrolling interests	(47,930)	25,080	(14,501)	(104,204)
Net (loss) income attributable to Vornado / Vornado Realty L.P.	(14,776)	96,946	192,141	251,017
Preferred share dividends / unit distributions	(16,176)	(19,096)	(48,531)	(59,920)
Preferred share / unit issuance costs (Series J redemption)	0	(7,408)	0	(7,408)
NET (LOSS) INCOME attributable to common shareholders & Class A unitholders	(30,952)	70,442	143,610	183,689
Earnings allocated to unvested participating securities	(740)	(589)	(2,499)	(2,001)
Numerator for basic and diluted (loss) income per share / per Class A unit	$ (31,692)	$ 69,853	$ 141,111	$ 181,688
Denominator:
Denominator for basic (loss) income per Class A unit – weighted average units	201,300	200,458	201,093	200,300
Vornado employee stock options and restricted share / unit awards (in shares)	1,813	1,683	2,218	1,632
Denominator for diluted (loss) income per Class A unit - weighted average units and assumed conversions	203,113	202,141	203,311	201,932
(LOSS) INCOME PER CLASS A UNIT – BASIC:
Income from continuing operations, net (in dollars per unit)	$ 0.08	$ 0.22	$ 0.77	$ 1.43
(Loss) income from discontinued operations, net (in dollars per unit)	(0.24)	0.13	(0.07)	(0.52)
Net (loss) income per Class A unit (in dollars per unit)	(0.16)	0.35	0.70	0.91
(LOSS) INCOME PER CLASS A UNIT – DILUTED:
Income from continuing operations, net (in dollars per unit)	0.08	0.22	0.76	1.42
(Loss) income from discontinued operations, net (in dollars per unit)	(0.24)	0.13	(0.07)	(0.52)
Net (loss) income per Class A unit (in dollars per unit)	$ (0.16)	$ 0.35	$ 0.69	$ 0.90