Income Per Share / Income Per Class A Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator:
Income from continuing operations, net of income attributable to noncontrolling interests									$ 449,356	$ 239,824	$ 526,686
Income (loss) from discontinued operations, net of income attributable to noncontrolling interests									598	(12,408)	380,231
Net income attributable to Vornado / Vornado Realty L.P.									449,954	227,416	906,917
Preferred share dividends / unit distributions									(50,636)	(65,399)	(75,903)
Preferred share / unit issuance cost									(14,486)	0	(7,408)
NET INCOME attributable to common shareholders / Class A unitholders	$ 100,494	$ 190,645	$ 111,534	$ (17,841)	$ 27,319	$ (29,026)	$ 115,972	$ 47,752	384,832	162,017	823,606
Earnings allocated to unvested participating securities									(44)	(46)	(96)
Numerator for basic (loss) income per share / per Class A unit									384,788	161,971	823,510
Earnings allocated to Out-Performance Plan units									174	230	806
Convertible preferred share dividends / unit distributions									62	0	86
Numerator for diluted income per share / per Class A unit									$ 385,024	$ 162,201	$ 824,402
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Denominator for basic income per share - weighted average shares (in shares)									190,219	189,526	188,837
Vornado stock options and restricted share awards (in shares)									933	1,448	1,064
Out-Performance Plan units									101	284	230
Convertible preferred shares / units									37	0	42
Denominator for diluted income per share - weighted average shares and assumed conversions (in shares)									191,290	191,258	190,173
INCOME PER COMMON SHARE – BASIC:
Income from continuing operations, net (in dollars per share)									$ 2.02	$ 0.92	$ 2.35
Income (loss) from discontinued operations, net (in dollars per share)									0.00	(0.07)	2.01
Net income per common share (in dollars per share)	$ 0.53	$ 1.00	$ 0.59	$ (0.09)	$ 0.14	$ (0.15)	$ 0.61	$ 0.25	2.02	0.85	4.36
INCOME PER COMMON SHARE – DILUTED:
Income (loss) from continuing operations, net (in dollars per share)									2.01	0.91	2.34
Income (loss) from discontinued operations, net (in dollars per share)									0.00	(0.06)	2.00
Net income per common share (in dollars per share)	$ 0.53	$ 1.00	$ 0.58	$ (0.09)	$ 0.14	$ (0.15)	$ 0.61	$ 0.25	$ 2.01	$ 0.85	$ 4.34
Vornado Realty L.P.
Numerator:
Income from continuing operations, net of income attributable to noncontrolling interests									$ 474,988	$ 251,554	$ 555,659
Income (loss) from discontinued operations, net of income attributable to noncontrolling interests									638	(13,228)	404,912
Net income attributable to Vornado / Vornado Realty L.P.									475,626	238,326	960,571
Preferred share dividends / unit distributions									(50,830)	(65,593)	(76,097)
Preferred share / unit issuance cost									(14,486)	0	(7,408)
NET INCOME attributable to common shareholders / Class A unitholders	$ 107,125	$ 203,268	$ 118,931	$ (19,014)	$ 29,123	$ (30,952)	$ 123,630	$ 50,932	410,310	172,733	877,066
Earnings allocated to unvested participating securities									(2,973)	(3,232)	(4,177)
Numerator for basic (loss) income per share / per Class A unit									407,337	169,501	872,889
Convertible preferred share dividends / unit distributions									62	0	86
Numerator for diluted income per share / per Class A unit									$ 407,399	$ 169,501	$ 872,975
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Denominator for basic income per Class A unit - weighted average units and assumed conversions									202,068	201,214	200,350
Vornado stock options and restricted share awards (in shares)									1,307	2,086	1,625
Out-Performance Plan units									37	0	42
Denominator for diluted income per Class A unit - weighted average units and assumed conversions									203,412	203,300	202,017
INCOME PER CLASS A UNIT – BASIC:
Income from continuing operations, net (in dollars per share)									$ 2.01	$ 0.91	$ 2.34
Income (loss) from discontinued operations, net (in dollars per share)									0.01	(0.07)	2.02
Net income per Class A unit (in dollars per share)	$ 0.53	$ 1.00	$ 0.58	$ (0.10)	$ 0.14	$ (0.16)	$ 0.61	$ 0.25	2.02	0.84	4.36
INCOME PER CLASS A UNIT – DILUTED:
Income from continuing operations, net (in dollars per share)									2.00	0.90	2.32
Income (loss) from discontinued operations, net (in dollars per share)									0.00	(0.07)	2.00
Net income per Class A unit (in dollars per share)	$ 0.52	$ 0.99	$ 0.58	$ (0.10)	$ 0.14	$ (0.16)	$ 0.61	$ 0.25	$ 2.00	$ 0.83	$ 4.32