Income Per Share /Income Per Class A Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator:
Income from continuing operations, net of income attributable to noncontrolling interests	$ 123,427	$ 115,112	$ 133,448	$ 164,631
Income from discontinued operations	641	16,989	300	31,351
Net income attributable to Vornado / Vornado Realty L.P.	124,068	132,101	133,748	195,982
Preferred share dividends / unit distributions	(12,534)	(16,129)	(25,569)	(32,258)
Preferred share / unit issuance costs	0	0	(14,486)	0
NET INCOME attributable to common shareholders / Class A unitholders	111,534	115,972	93,693	163,724
Earnings allocated to unvested participating securities	(11)	(13)	(22)	(27)
Numerator for basic income per share / per Class A unit	111,523	115,959	93,671	163,697
Convertible preferred share dividends / unit distributions	16	20	0	0
Earnings allocated to Out-Performance Plan units	0	0	37	233
Numerator for diluted income per share	$ 111,539	$ 115,979	$ 93,708	$ 163,930
Denominator:
Denominator for basic income per share - weighted average shares (in shares)	190,200	189,395	190,141	189,304
Vornado employee stock options and restricted share / unit awards (in shares)	930	1,011	934	1,089
Convertible preferred shares/units	38	38	0	0
Out-Performance Plan units	0	0	115	281
Denominator for diluted income per share - weighted average shares and assumed conversions (in shares)	191,168	190,444	191,190	190,674
INCOME PER COMMON SHARE – BASIC:
Income from continuing operations, net (in dollars per share)	$ 0.59	$ 0.52	$ 0.49	$ 0.70
Income from discontinued operations, net (in dollars per share)	0.00	0.09	0.00	0.16
Net income per common share (in dollars per share)	0.59	0.61	0.49	0.86
INCOME PER COMMON SHARE – DILUTED:
Income from continuing operations, net (in dollars per share)	0.58	0.52	0.49	0.70
Income from discontinued operations, net (in dollars per share)	0.00	0.09	0.00	0.16
Net income per common share (in dollars per share)	$ 0.58	$ 0.61	$ 0.49	$ 0.86
Vornado Realty L.P.
Numerator:
Income from continuing operations, net of income attributable to noncontrolling interests	$ 130,830	$ 121,696	$ 139,749	$ 173,488
Income from discontinued operations	683	18,111	320	33,429
Net income attributable to Vornado / Vornado Realty L.P.	131,513	139,807	140,069	206,917
Preferred share dividends / unit distributions	(12,582)	(16,177)	(25,666)	(32,355)
Preferred share / unit issuance costs	0	0	(14,486)	0
NET INCOME attributable to common shareholders / Class A unitholders	118,931	123,630	99,917	174,562
Earnings allocated to unvested participating securities	(772)	(742)	(1,544)	(1,759)
Numerator for basic income per share / per Class A unit	118,159	122,888	98,373	172,803
Convertible preferred share dividends / unit distributions	16	20	0	0
Numerator for diluted income per Class A unit	$ 118,175	$ 122,908	$ 98,373	$ 172,803
Denominator:
Denominator for basic income per Class A unit – weighted average units (in shares)	202,064	201,127	201,997	200,987
Vornado employee stock options and restricted share / unit awards (in shares)	1,252	1,458	1,269	1,630
Convertible preferred shares/units	38	38	0	0
Denominator for diluted income per Class A unit - weighted average units and assumed conversions	203,354	202,623	203,266	202,617
INCOME PER CLASS A UNIT – BASIC:
Income from continuing operations, net (in dollars per unit)	$ 0.58	$ 0.52	$ 0.49	$ 0.69
Income from discontinued operations, net (in dollars per unit)	0.00	0.09	0.00	0.17
Net income per Class A unit (in dollars per unit)	0.58	0.61	0.49	0.86
INCOME PER CLASS A UNIT – DILUTED:
Income from continuing operations, net (in dollars per unit)	0.58	0.52	0.48	0.69
Income from discontinued operations, net (in dollars per unit)	0.00	0.09	0.00	0.16
Net income per Class A unit (in dollars per unit)	$ 0.58	$ 0.61	$ 0.48	$ 0.85