Consolidated Statements of Changes in Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Real estate fund investments	Other	Preferred Shares	Common Shares	Additional Capital	Earnings Less Than Distributions	Accumulated Other Comprehensive Loss	Non-controlling Interests in Consolidated Subsidiaries	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. Real estate fund investments	Vornado Realty L.P. Other	Vornado Realty L.P. Preferred Shares	Vornado Realty L.P. Class A Units Owned by Vornado	Vornado Realty L.P. Earnings Less Than Distributions	Vornado Realty L.P. Accumulated Other Comprehensive 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	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment Earnings Less Than Distributions	Cumulative Effect, Period of Adoption, Adjustment Vornado Realty L.P.	Cumulative Effect, Period of Adoption, Adjustment Vornado Realty L.P. Earnings Less Than Distributions
Beginning balance, shares at Dec. 31, 2018				36,800	190,535										36,800	190,535
Beginning balance, value at Dec. 31, 2018	$ 5,107,883			$ 891,294	$ 7,600	$ 7,725,857	$ (4,167,184)	$ 7,664	$ 642,652			$ 5,107,883			$ 891,294	$ 7,733,457	$ (4,167,184)	$ 7,664	$ 642,652
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income attributable to Vornado / Vornado Realty L.P.	2,942,187						2,942,187					3,139,541					3,139,541
Net income attributable to redeemable partnership units	(197,354)											(197,354)					(197,354)
Net loss attributable to nonredeemable noncontrolling interests in consolidated subsidiaries	34,045								34,045			34,045							34,045
Dividends on common shares	(377,750)						(377,750)
Distributions to Vornado												(377,750)					(377,750)
Distributions to preferred shareholders / unitholders (see Note 13 for distributions per unit amounts)	(37,598)						(37,598)					(37,598)					(37,598)
Common shares issued: / Class A Units issued to Vornado
Upon redemption of Class A units, at redemption value, shares					123											123
Upon redemption of Class A units, at redemption value, value	8,128				$ 5	8,123						8,128				$ 8,128
Under employees' share option plan, shares					165											165
Under employees' share option plan, value	(7,347)				$ 7	1,338	(8,692)					(7,347)				$ 1,345	(8,692)
Under dividend reinvestment plan, shares					16											16
Under dividend reinvestment plan, value	1,058				$ 1	1,057						1,058				$ 1,058
Contributions:
Contributions		$ 3,384	$ 5,839							$ 3,384	$ 5,839		$ 3,384	$ 5,839						$ 3,384	$ 5,839
Distributions:
Distributions		(6)	(39,290)							(6)	(39,290)		(6)	(39,290)						(6)	(39,290)
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units, shares				(2)	3
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units, value	0			$ (38)		38
Preferred unit issuance, shares															(2)	3
Preferred unit issuance, value												0			$ (38)	$ 38
Deferred compensation shares and options, shares					8											8
Deferred compensation shares and options	829					829						829				$ 829
Amounts reclassified from accumulated other comprehensive loss relating to a nonconsolidated subsidiary	(2,311)							(2,311)				(2,311)						(2,311)
Other comprehensive (loss) income of nonconsolidated subsidiaries	(949)							(949)				(949)						(949)
Increase (reduction) in value of interest rate swaps and other	(55,497)							(55,497)				(55,497)						(55,497)
Unearned Out-Performance Plan awards acceleration	11,720					11,720						11,720				11,720
Redeemable Class A unit measurement adjustment	123,635					123,635						123,635				$ 123,635
Redeemable noncontrolling interests' share of above adjustments	3,732							3,732				3,732						3,732
Deconsolidation of partially owned entity	(11,441)								(11,441)			(11,441)							(11,441)
Other, shares				1											(1)
Other, value	5						2	2	1			5					2	2	1
Ending balance, shares at Sep. 30, 2019				36,797	190,850										36,797	190,850
Ending balance, value at Sep. 30, 2019	7,710,256			$ 891,256	$ 7,613	7,872,597	(1,649,035)	(47,359)	635,184			7,710,256			$ 891,256	$ 7,880,210	(1,649,035)	(47,359)	635,184
Beginning balance, shares at Jun. 30, 2019				36,797	190,813										36,797	190,813
Beginning balance, value at Jun. 30, 2019	7,496,144			$ 891,256	$ 7,611	7,845,748	(1,845,995)	(38,066)	635,590			7,496,144			$ 891,256	$ 7,853,359	(1,845,995)	(38,066)	635,590
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income attributable to Vornado / Vornado Realty L.P.	335,438						335,438					358,075					358,075
Net income attributable to redeemable partnership units	(22,637)											(22,637)					(22,637)
Net loss attributable to nonredeemable noncontrolling interests in consolidated subsidiaries	5,774								5,774			5,774							5,774
Dividends on common shares	(125,947)						(125,947)
Distributions to Vornado												(125,947)					(125,947)
Distributions to preferred shareholders / unitholders (see Note 13 for distributions per unit amounts)	(12,532)						(12,532)					(12,532)					(12,532)
Common shares issued: / Class A Units issued to Vornado
Upon redemption of Class A units, at redemption value, shares					31											31
Upon redemption of Class A units, at redemption value, value	1,999				$ 1	1,998						1,999				$ 1,999
Under dividend reinvestment plan, shares					6											6
Under dividend reinvestment plan, value	357				$ 1	356						357				$ 357
Contributions:
Contributions	908								908			908							908
Distributions:
Distributions		(6)	(7,086)							(6)	(7,086)		(6)	(7,086)						(6)	(7,086)
Deferred compensation shares and options	266					266						266				266
Amounts reclassified from accumulated other comprehensive loss relating to a nonconsolidated subsidiary	0											0
Other comprehensive (loss) income of nonconsolidated subsidiaries	11							11				11						11
Increase (reduction) in value of interest rate swaps and other	(9,953)					0		(9,953)				(9,953)						(9,953)
Redeemable Class A unit measurement adjustment	24,228					24,228						24,228				24,228
Redeemable noncontrolling interests' share of above adjustments	650							650				650						650
Other, value	5					1	1	(1)	4			5				$ 1	1	(1)	4
Ending balance, shares at Sep. 30, 2019				36,797	190,850										36,797	190,850
Ending balance, value at Sep. 30, 2019	7,710,256			$ 891,256	$ 7,613	7,872,597	(1,649,035)	(47,359)	635,184			7,710,256			$ 891,256	$ 7,880,210	(1,649,035)	(47,359)	635,184
Beginning balance, shares at Dec. 31, 2019				36,796	190,986										36,796	190,986
Beginning balance, value at Dec. 31, 2019	7,310,978			$ 891,214	$ 7,618	7,827,697	(1,954,266)	(40,233)	578,948			7,310,978			$ 891,214	$ 7,835,315	(1,954,266)	(40,233)	578,948			$ (16,064)	$ (16,064)	$ (16,064)	$ (16,064)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income attributable to Vornado / Vornado Realty L.P.	(102,026)						(102,026)					(112,116)					(112,116)
Net income attributable to redeemable partnership units	10,090											10,090					10,090
Net loss attributable to nonredeemable noncontrolling interests in consolidated subsidiaries	(141,310)								(141,310)			(141,310)							(141,310)
Dividends on common shares	(353,558)						(353,558)
Distributions to Vornado												(353,558)					(353,558)
Distributions to preferred shareholders / unitholders (see Note 13 for distributions per unit amounts)	(37,591)						(37,591)					(37,591)					(37,591)
Common shares issued: / Class A Units issued to Vornado
Upon redemption of Class A units, at redemption value, shares					149											149
Upon redemption of Class A units, at redemption value, value	6,050				$ 6	6,044						6,050				$ 6,050
Under employees' share option plan, shares					69											69
Under employees' share option plan, value	3,517				$ 3	3,514						3,517				$ 3,517
Under dividend reinvestment plan, shares					40											40
Under dividend reinvestment plan, value	2,050				$ 2	2,048						2,050				$ 2,050
Contributions:
Contributions		$ 3,389	$ 2,837							$ 3,389	$ 2,837		$ 3,389	$ 2,837						$ 3,389	$ 2,837
Distributions:
Distributions	(25,517)								(25,517)			(25,517)							(25,517)
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units, shares				(3)	4										(3)	4
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units, value	0			$ (57)		57						0			$ (57)	$ 57
Deferred compensation shares and options, shares					13											13
Deferred compensation shares and options	769				$ 1	905	(137)					769				$ 906	(137)
Amounts reclassified from accumulated other comprehensive loss relating to a nonconsolidated subsidiary	0											0
Other comprehensive (loss) income of nonconsolidated subsidiaries	(15,626)							(15,626)				(15,626)						(15,626)
Increase (reduction) in value of interest rate swaps and other	(37,473)							(37,473)				(37,473)						(37,473)
Unearned Out-Performance Plan awards acceleration	10,824					10,824						10,824				10,824
Redeemable Class A unit measurement adjustment	272,436					272,436						272,436				272,436
Redeemable noncontrolling interests' share of above adjustments	3,498							3,498				3,498						3,498
Other, value	(1,498)			$ (1)	$ (1)	(1)	7		(1,502)			(1,498)			$ (1)	$ (2)	7		(1,502)
Ending balance, shares at Sep. 30, 2020				36,793	191,261										36,793	191,261
Ending balance, value at Sep. 30, 2020	6,885,685			$ 891,156	$ 7,629	8,123,524	(2,463,635)	(89,834)	416,845			6,885,685			$ 891,156	$ 8,131,153	(2,463,635)	(89,834)	416,845
Beginning balance, shares at Jun. 30, 2020				36,794	191,151										36,794	191,151
Beginning balance, value at Jun. 30, 2020	6,928,909			$ 891,164	$ 7,625	8,095,774	(2,415,500)	(82,646)	432,492			6,928,909			$ 891,164	$ 8,103,399	(2,415,500)	(82,646)	432,492
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income attributable to Vornado / Vornado Realty L.P.	65,700						65,700					69,584					69,584
Net income attributable to redeemable partnership units	(3,884)											(3,884)					(3,884)
Net loss attributable to nonredeemable noncontrolling interests in consolidated subsidiaries	(1,019)								(1,019)			(1,019)							(1,019)
Dividends on common shares	(101,311)						(101,311)
Distributions to Vornado												(101,311)					(101,311)
Distributions to preferred shareholders / unitholders (see Note 13 for distributions per unit amounts)	(12,530)						(12,530)					(12,530)					(12,530)
Common shares issued: / Class A Units issued to Vornado
Upon redemption of Class A units, at redemption value, shares					100											100
Upon redemption of Class A units, at redemption value, value	3,586				$ 4	3,582						3,586				$ 3,586
Under dividend reinvestment plan, shares					9											9
Under dividend reinvestment plan, value	300				$ 1	299						300				$ 300
Contributions:
Contributions	358								358			358							358
Distributions:
Distributions	(14,987)								(14,987)			(14,987)							(14,987)
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units, shares				(1)											(1)	0
Conversion of Series A preferred shares to common shares / Conversion of Series A preferred units to Class A units, value	0			$ (7)		7						0			$ (7)	$ 7
Deferred compensation shares and options, shares																0
Deferred compensation shares and options	304					304						304				$ 304
Amounts reclassified from accumulated other comprehensive loss relating to a nonconsolidated subsidiary	0											0
Other comprehensive (loss) income of nonconsolidated subsidiaries	(15,634)							(15,634)				(15,634)						(15,634)
Increase (reduction) in value of interest rate swaps and other	7,926							7,926				7,926						7,926
Redeemable Class A unit measurement adjustment	23,557					23,557						23,557				$ 23,557
Redeemable noncontrolling interests' share of above adjustments	520							520				520						520
Other, shares					(1)											(1)
Other, value	6			$ (1)	$ (1)	1	6		1			6			$ (1)		6		1
Ending balance, shares at Sep. 30, 2020				36,793	191,261										36,793	191,261
Ending balance, value at Sep. 30, 2020	$ 6,885,685			$ 891,156	$ 7,629	$ 8,123,524	$ (2,463,635)	$ (89,834)	$ 416,845			$ 6,885,685			$ 891,156	$ 8,131,153	$ (2,463,635)	$ (89,834)	$ 416,845