Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Total Revenues	$ 627,596	$ 578,710	$ 1,850,686	$ 1,715,502
Total expenses	436,156	396,571	1,298,141	1,198,854
Operating income (loss)	191,440	182,139	552,545	516,648
(Loss) income from partially owned entities	(325)	(26,034)	(8,709)	(78,676)
Income from real estate fund investments	1,665	24,160	52,122	142,418
Interest and other investment (loss) income, net	3,160	7,568	19,618	28,814
Interest and debt expense	(95,344)	(100,817)	(279,110)	(301,042)
Net gain on disposition of wholly owned and partially owned assets	103,037	2,665	104,897	13,205
Income (loss) before income taxes	203,633	89,681	441,363	321,367
Income tax benefit (expense)	(2,856)	(2,652)	84,245	(6,783)
Income (loss) from continuing operations	200,777	87,029	525,608	314,584
Income from discontinued operations	34,463	82,168	50,278	118,456
Net income	235,240	169,197	575,886	433,040
Less net income attributable to noncontrolling interests	(16,006)	(17,673)	(66,559)	(101,791)
Net income attributable to Vornado	219,234	151,524	509,327	331,249
Interest and debt expense (2)	118,977	160,252	348,725	510,724
Depreciation and amortization (2)	174,209	160,270	493,904	530,052
Income tax (benefit) expense (2)	3,043	2,232	(85,349)	21,489
EBITDA	515,463	474,278	1,266,607	1,393,514
New York Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	429,433	383,828	1,243,208	1,120,686
Total expenses	263,805	238,153	766,863	702,727
Operating income (loss)	165,628	145,675	476,345	417,959
(Loss) income from partially owned entities	4,010	5,810	1,523	16,372
Interest and other investment (loss) income, net	1,888	1,834	5,642	4,889
Interest and debt expense	(50,480)	(43,061)	(143,004)	(134,970)
Income (loss) before income taxes	121,046	110,258	340,506	304,250
Income tax benefit (expense)	(1,147)	(802)	(3,185)	(2,997)
Income (loss) from continuing operations	119,899	109,456	337,321	301,253
Income from discontinued operations		5,615		17,401
Net income	119,899	115,071	337,321	318,654
Less net income attributable to noncontrolling interests	(2,582)	(2,690)	(6,640)	(7,203)
Net income attributable to Vornado	117,317	112,381	330,681	311,451
Interest and debt expense (2)	64,653	58,010	184,377	180,150
Depreciation and amortization (2)	99,206	79,446	288,897	241,040
Income tax (benefit) expense (2)	1,214	746	3,368	3,069
EBITDA	282,390	250,583	807,323	735,710
Washington DC Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	132,704	133,541	401,528	403,645
Total expenses	102,114	88,375	293,772	265,299
Operating income (loss)	30,590	45,166	107,756	138,346
(Loss) income from partially owned entities	(1,909)	(1,411)	(3,583)	(4,925)
Interest and other investment (loss) income, net	34	15	60	93
Interest and debt expense	(16,580)	(18,685)	(52,223)	(56,692)
Net gain on disposition of wholly owned and partially owned assets	102,404		102,404
Income (loss) before income taxes	114,539	25,085	154,414	76,822
Income tax benefit (expense)	(287)	(130)	(79)	(46)
Income (loss) from continuing operations	114,252	24,955	154,335	76,776
Net income	114,252	24,955	154,335	76,776
Net income attributable to Vornado	114,252	24,955	154,335	76,776
Interest and debt expense (2)	20,010	22,208	62,413	67,469
Depreciation and amortization (2)	48,132	36,411	136,687	108,367
Income tax (benefit) expense (2)	294	145	(1,856)	88
EBITDA	182,688	83,719	351,579	252,700
Other Segment [Member]
Segment Reporting Information [Line Items]
Total Revenues	65,459	61,341	205,950	191,171
Total expenses	70,237	70,043	237,506	230,828
Operating income (loss)	(4,778)	(8,702)	(31,556)	(39,657)
(Loss) income from partially owned entities	(2,426)	(30,433)	(6,649)	(90,123)
Income from real estate fund investments	1,665	24,160	52,122	142,418
Interest and other investment (loss) income, net	1,238	5,719	13,916	23,832
Interest and debt expense	(28,284)	(39,071)	(83,883)	(109,380)
Net gain on disposition of wholly owned and partially owned assets	633	2,665	2,493	13,205
Income (loss) before income taxes	(31,952)	(45,662)	(53,557)	(59,705)
Income tax benefit (expense)	(1,422)	(1,720)	87,509	(3,740)
Income (loss) from continuing operations	(33,374)	(47,382)	33,952	(63,445)
Income from discontinued operations	34,463	76,553	50,278	101,055
Net income	1,089	29,171	84,230	37,610
Less net income attributable to noncontrolling interests	(13,424)	(14,983)	(59,919)	(94,588)
Net income attributable to Vornado	(12,335)	14,188	24,311	(56,978)
Interest and debt expense (2)	34,314	80,034	101,935	263,105
Depreciation and amortization (2)	26,871	44,413	68,320	180,645
Income tax (benefit) expense (2)	1,535	1,341	(86,861)	18,332
EBITDA	$ 50,385	$ 139,976	$ 107,705	$ 405,104