Consolidated Statements of Changes in Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Redeemable Preferred Unit	Series J	JBGS	Real estate fund investments	Other	Preferred Shares / Units	Preferred Shares / Units Cumulative Redeemable Preferred Unit	Common Shares	Additional Capital	Earnings Less Than Distributions	Earnings Less Than Distributions JBGS	Accumulated Other Comprehensive Income (Loss)	Non- controlling Interests in Consolidated Subsidiaries	Non- controlling Interests in Consolidated Subsidiaries JBGS	Non- controlling Interests in Consolidated Subsidiaries Real estate fund investments	Non- controlling Interests in Consolidated Subsidiaries Other	Vornado Realty L.P.	Vornado Realty L.P. Cumulative Redeemable Preferred Unit	Vornado Realty L.P. JBGS	Vornado Realty L.P. Real estate fund investments	Vornado Realty L.P. Other	Vornado Realty L.P. Preferred Shares / Units	Vornado Realty L.P. Preferred Shares / Units Cumulative Redeemable Preferred Unit	Vornado Realty L.P. Preferred Shares / Units Series J	Vornado Realty L.P. Class A Units Owned by Vornado	Vornado Realty L.P. Earnings Less Than Distributions	Vornado Realty L.P. Earnings Less Than Distributions Series J	Vornado Realty L.P. Earnings Less Than Distributions JBGS	Vornado Realty L.P. Accumulated Other Comprehensive Income (Loss)	Vornado Realty L.P. Non- controlling Interests in Consolidated Subsidiaries	Vornado Realty L.P. Non- controlling Interests in Consolidated Subsidiaries Real estate fund investments	Vornado Realty L.P. Non- controlling Interests in Consolidated Subsidiaries Other
Beginning balance, Shares at Dec. 31, 2014							52,679		187,887														52,679			187,887
Beginning balance, Value at Dec. 31, 2014	$ 7,489,382						$ 1,277,026		$ 7,493	$ 6,873,025	$ (1,505,385)		$ 93,267	$ 743,956				$ 7,489,382					$ 1,277,026			$ 6,880,518	$ (1,505,385)			$ 93,267	$ 743,956
Net income attributable to Vornado / Vornado Realty L.P.	760,434										760,434							803,665									803,665
Net income attributable to redeemable partnership units	(43,231)																	(43,231)									(43,231)
Net income attributable to noncontrolling interests in consolidated subsidiaries	55,765				$ 40,117									55,765				55,765													55,765
Distribution of Urban Edge Properties	(464,603)										(464,262)			(341)				(464,603)									(464,262)				(341)
Dividends on common shares	(474,751)										(474,751)
Distributions to Vornado																		(474,751)									(474,751)
Dividends on preferred shares / Distributions to preferred unitholders	(80,578)										(80,578)							(80,578)									(80,578)
Common shares issued:
Upon redemption of Class A units, at redemption value, Shares									452																	452
Upon redemption of Class A units, at redemption value, Value	48,230								$ 18	48,212								48,230								$ 48,230
Under employees' share option plan, Shares									214																	214
Under employees' share option plan, Value	12,762								$ 9	15,332	(2,579)							12,762								$ 15,341	(2,579)
Under dividend reinvestment plan, Shares									14																	14
Under dividend reinvestment plan, Value	1,438								$ 1	1,437								1,438								$ 1,438
Contributions
Contributions					51,725	$ 250										$ 51,725	$ 250				$ 51,725	$ 250										$ 51,725	$ 250
Distributions:
Distributions					(72,114)	(525)										(72,114)	(525)				(72,114)	(525)										(72,114)	(525)
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units							(2)		4														(2)			4
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units, Value	0						$ (72)		$ 1	71													$ (72)			$ 72
Deferred compensation shares / units and options, Shares									6																	6
Deferred compensation shares / units and options, Value	2,080								$ 1	2,438	(359)							2,080								$ 2,439	(359)
(Reduction) increase in unrealized net gain on available-for-sale securities	(55,326)												(55,326)					(55,326)												(55,326)
Pro rata share of other comprehensive income (loss) of nonconsolidated subsidiaries	(327)												(327)					(327)												(327)
Increase in value of interest rate swaps	6,435												6,435					6,435												6,435
Adjustments to carry redeemable Class A units at redemption value	192,464									192,464								192,464								192,464
Redeemable noncontrolling interests' share of above adjustments	(2,866)												(2,866)					2,866												2,866
Other, Shares									0
Other	471						$ 0		$ (2)	0	700		6	(233)				471					$ 0			$ (2)	700			6	(233)
Ending balance, Shares at Dec. 31, 2015							52,677		188,577														52,677			188,577
Ending balance, Value at Dec. 31, 2015	7,476,078						$ 1,276,954		$ 7,521	7,132,979	(1,766,780)		46,921	778,483				7,476,078					$ 1,276,954			$ 7,140,500	(1,766,780)			46,921	778,483
Net income attributable to Vornado / Vornado Realty L.P.	906,917										906,917							960,571									960,571
Net income attributable to redeemable partnership units	(53,654)																	(53,654)									(53,654)
Net income attributable to noncontrolling interests in consolidated subsidiaries	21,351				(2,560)									21,351				21,351													21,351
Distribution of Urban Edge Properties																		(475,961)									(475,961)				0
Dividends on common shares	(475,961)										(475,961)
Distributions to Vornado																		(75,903)									(75,903)
Dividends on preferred shares / Distributions to preferred unitholders	(75,903)										(75,903)							(246,250)									(7,408)
Redemption of preferred shares, Shares / Units																									(9,850)
Redemption of preferred shares, Value			$ (246,250)																						$ (238,842)			$ (7,408)
Common shares issued:
Upon redemption of Class A units, at redemption value, Shares									376																	376
Upon redemption of Class A units, at redemption value, Value	36,510								$ 15	36,495								36,510								$ 36,510
Under employees' share option plan, Shares									123																	123
Under employees' share option plan, Value	6,825								$ 5	6,820	0							6,825								$ 6,825	0
Under dividend reinvestment plan, Shares									16																	16
Under dividend reinvestment plan, Value	1,444								$ 1	1,443								1,444								$ 1,444
Contributions
Contributions	19,749													19,749				19,749													19,749
Distributions:
Distributions	(31,342)				(62,444)	(36,804)										(62,444)	(36,804)				(62,444)	(36,804)										(62,444)	(36,804)
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units							(2)		3														(2)			3
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units, Value							$ (56)		$ 0	56								0					$ (56)			$ 56
Deferred compensation shares / units and options, Shares									7																	7
Deferred compensation shares / units and options, Value	1,602								$ 0	1,788	(186)							1,602								$ 1,788	(186)
(Reduction) increase in unrealized net gain on available-for-sale securities	52,057												52,057					52,057												52,057
Pro rata share of other comprehensive income (loss) of nonconsolidated subsidiaries	(2,739)												(2,739)					(2,739)												(2,739)
Increase in value of interest rate swaps	27,434												27,434					27,434												27,434
Adjustments to carry redeemable Class A units at redemption value	(26,251)									(26,251)								(26,251)								$ (26,251)
Redeemable noncontrolling interests' share of above adjustments	(4,699)												(4,699)					(4,699)												(4,699)
Other, Shares									(1)																	(1)
Other	(420)						$ (1)			2	(61)		(2)	(358)				(420)					$ (1)			$ 2	(61)			(2)	(358)
Ending balance, Shares at Dec. 31, 2016							42,825		189,101														42,825			189,101
Ending balance, Value at Dec. 31, 2016	7,618,496						$ 1,038,055		$ 7,542	7,153,332	(1,419,382)		118,972	719,977				7,618,496					$ 1,038,055			$ 7,160,874	(1,419,382)			118,972	719,977
Net income attributable to Vornado / Vornado Realty L.P.	227,416										227,416							238,326									238,326
Net income attributable to redeemable partnership units	(10,910)																	(10,910)									(10,910)
Net income attributable to noncontrolling interests in consolidated subsidiaries	25,802				14,044									25,802				25,802													25,802
Dividends on common shares	(496,490)										(496,490)
Distributions to Vornado																		(496,490)									(496,490)
Dividends on preferred shares / Distributions to preferred unitholders	(65,399)										(65,399)							(65,399)									(65,399)
Redemption of preferred shares, Shares / Units																							(9,850)
Redemption of preferred shares, Value																							$ (238,842)
Common shares issued:
Upon redemption of Class A units, at redemption value, Shares									403																	403
Upon redemption of Class A units, at redemption value, Value	38,747								$ 16	38,731								38,747								$ 38,747
Under employees' share option plan, Shares									449																	449
Under employees' share option plan, Value	28,253								$ 18	28,235								28,253								$ 28,253
Under dividend reinvestment plan, Shares									17																	17
Under dividend reinvestment plan, Value	1,459								$ 1	1,458								1,459								$ 1,459
Contributions
Contributions	1,044													1,044				1,044													1,044
Distributions:
Distributions	(33,229)			$ (2,428,345)	$ (73,850)	$ (2,618)						$ (2,428,345)			$ 0	$ (73,850)	$ (2,618)			$ (2,428,345)	$ (73,850)	$ (2,618)							$ (2,428,345)			$ (73,850)	$ (2,618)
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units							(5)		10														(5)			10
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units, Value	0						$ (162)		$ 0	162	0							0					$ (162)			$ 162
Deferred compensation shares / units and options, Shares									0																	0
Deferred compensation shares / units and options, Value	1,828									2,246	(418)		0					1,828								$ 2,246	(418)
(Reduction) increase in unrealized net gain on available-for-sale securities	(20,951)												(20,951)					(20,951)												(20,951)
Pro rata share of amounts reclassified related to a nonconsolidated subsidiary	(14,402)												(14,402)					14,402												14,402
Pro rata share of other comprehensive income (loss) of nonconsolidated subsidiaries	1,425												1,425					1,425												1,425
Increase in value of interest rate swaps	15,476												15,476					15,476												15,476
Adjustments to carry redeemable Class A units at redemption value	268,494									268,494								268,494								$ 268,494
Preferred shares issuance, Shares							12,780																12,780
Preferred shares issuance, Value	309,609						$ 309,609											309,609					$ 309,609
Cumulative redeemable preferred shares called for redemption, units								(18,800)																18,800
Cumulative redeemable preferred shares called for redemption		$ (455,514)						$ (455,514)											$ (455,514)					$ (455,514)
Redeemable noncontrolling interests' share of above adjustments	(642)												(642)					(642)												(642)
Other, Shares									4														0			4
Other	(941)										(635)			(306)				(941)					$ 0			$ 0	(635)			0	(306)
Ending balance, Shares at Dec. 31, 2017							36,800		189,984														36,800			189,984
Ending balance, Value at Dec. 31, 2017	$ 5,007,701						$ 891,988		$ 7,577	$ 7,492,658	$ (4,183,253)		$ 128,682	$ 670,049				$ 5,007,701					$ 891,988			$ 7,500,235	$ (4,183,253)			$ 128,682	$ 670,049