Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash Flows from Operating Activities:
Net (loss) income	$ (253,119)	$ 3,173,586
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Equity in net loss (income) of partially owned entities	353,679	(56,139)
Net gains on disposition of wholly owned and partially owned assets	(338,862)	(641,664)
Depreciation and amortization (including amortization of deferred financing costs)	305,905	341,951
Net unrealized loss on real estate fund investments	225,412	16,162
Distributions of income from partially owned entities	132,850	66,252
Non-cash (gain on extinguishment of 608 Fifth Avenue lease liability) impairment loss on 608 Fifth Avenue right-of-use asset	(70,260)	75,220
Write-off of lease receivables deemed uncollectible	60,766	16,488
Stock-based compensation expense	39,638	48,045
Straight-lining of rents	20,021	8,446
Credit losses on loans receivable	13,369	0
Amortization of below-market leases, net	(13,054)	(15,561)
Decrease in fair value of marketable securities	4,938	3,095
Net gain on transfer to Fifth Avenue and Times Square JV	0	(2,571,099)
Real estate impairment losses	0	26,140
Prepayment penalty on redemption of senior unsecured notes due 2022	0	22,058
Other non-cash adjustments	7,544	3,406
Changes in operating assets and liabilities:
Real estate fund investments	(6,502)	(4,000)
Tenant and other receivables, net	(27,093)	(28,110)
Prepaid assets	(215,645)	(74,502)
Other assets	(41,328)	(10,195)
Accounts payable and accrued expenses	(4,058)	1,496
Other liabilities	(2,841)	(3,104)
Net cash provided by operating activities	191,360	397,971
Cash Flows from Investing Activities:
Proceeds from sale of condominium units at 220 Central Park South	939,292	1,039,493
Development costs and construction in progress	(448,167)	(448,281)
Moynihan Train Hall expenditures	(277,128)	(352,211)
Additions to real estate	(112,906)	(189,579)
Proceeds from sales of marketable securities	28,375	168,314
Investments in partially owned entities	(6,156)	(16,480)
Distributions of capital from partially owned entities	1,090	24,880
Acquisitions of real estate and other	(985)	(3,260)
Proceeds from transfer of interest in Fifth Avenue and Times Square JV (net of $35,562 of transaction costs and $10,899 of deconsolidated cash and restricted cash)	0	1,248,743
Proceeds from redemption of 640 Fifth Avenue preferred equity	0	500,000
Proceeds from sale of real estate and related investments	0	255,534
Proceeds from repayments of loans receivable	0	1,395
Net cash provided by investing activities	123,415	2,228,548
Cash Flows from Financing Activities:
Dividends paid on common shares / Distributions to Vornado	(725,938)	(377,750)
Proceeds from borrowings	555,918	1,107,852
Repayments of borrowings	(514,493)	(2,635,028)
Moynihan Train Hall reimbursement from Empire State Development	277,128	352,211
Contributions from noncontrolling interests / noncontrolling interests in consolidated subsidiaries	98,626	9,223
Distribution to noncontrolling interests / redeemable security holders and noncontrolling interests in consolidated subsidiaries	(76,759)	(65,084)
Dividends paid on preferred shares / Distributions to preferred unitholders	(50,123)	(37,598)
Proceeds received from exercise of employee share options (Vornado stock options) and other	5,567	2,403
Debt issuance costs	(1,357)	(15,328)
Repurchase of shares (Class A units) related to stock compensation arrangements and related tax withholdings	(137)	(8,692)
Purchase of marketable securities in connection with defeasance of mortgage payable	0	(407,126)
Prepayment penalty on redemption of senior unsecured notes due 2022	0	(22,058)
Redemption of preferred shares / units	0	(893)
Net cash used in financing activities	(431,568)	(2,097,868)
Net (decrease) increase in cash and cash equivalents and restricted cash	(116,793)	528,651
Cash and cash equivalents and restricted cash at beginning of period	1,607,131	716,905
Cash and cash equivalents and restricted cash at end of period	1,490,338	1,245,556
Reconciliation of Cash and Cash Equivalents and Restricted Cash:
Cash and cash equivalents at beginning of period	1,515,012	570,916
Restricted cash at beginning of period	92,119	145,989
Cash and cash equivalents and restricted cash at beginning of period	1,607,131	716,905
Cash and cash equivalents at end of period	1,411,047	1,132,491
Restricted cash at end of period	79,291	113,065
Cash and cash equivalents and restricted cash at end of period	1,490,338	1,245,556
Supplemental Disclosure of Cash Flow Information:
Cash payments for interest, excluding capitalized interest of $30,649 and $55,186	164,752	227,310
Cash payments for income taxes	14,252	47,345
Non-Cash Investing and Financing Activities:
Reclassification of condominium units from "development costs and construction in progress" to "220 Central Park South condominium units ready for sale"	370,850	825,520
Redeemable Class A unit measurement adjustment	272,436	123,635
Accrued capital expenditures included in accounts payable and accrued expenses	118,672	117,205
Write-off of fully depreciated assets	(111,863)	(113,261)
Investments received in exchange for transfer to Fifth Avenue and Times Square JV:
Preferred equity	0	2,327,750
Common equity	0	1,449,495
Lease liabilities arising from the recognition of right-of-use assets	0	526,866
Marketable securities transferred in connection with the defeasance of mortgage payable	0	(407,126)
Defeasance of mortgage payable	0	390,000
Amounts related to our investment in Pennsylvania Real Estate Investment Trust reclassified from "investments in partially owned entities" and "accumulated other comprehensive loss" to "marketable securities" upon conversion of operating partnership units to common shares	0	54,962
Vornado Realty L.P.
Cash Flows from Operating Activities:
Net (loss) income	(253,119)	3,173,586
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Equity in net loss (income) of partially owned entities	353,679	(56,139)
Net gains on disposition of wholly owned and partially owned assets	(338,862)	(641,664)
Depreciation and amortization (including amortization of deferred financing costs)	305,905	341,951
Net unrealized loss on real estate fund investments	225,412	16,162
Distributions of income from partially owned entities	132,850	66,252
Non-cash (gain on extinguishment of 608 Fifth Avenue lease liability) impairment loss on 608 Fifth Avenue right-of-use asset	(70,260)	75,220
Write-off of lease receivables deemed uncollectible	60,766	16,488
Stock-based compensation expense	39,638	48,045
Straight-lining of rents	20,021	8,446
Credit losses on loans receivable	13,369	0
Amortization of below-market leases, net	(13,054)	(15,561)
Decrease in fair value of marketable securities	4,938	3,095
Net gain on transfer to Fifth Avenue and Times Square JV	0	(2,571,099)
Real estate impairment losses	0	26,140
Prepayment penalty on redemption of senior unsecured notes due 2022	0	22,058
Other non-cash adjustments	7,544	3,406
Changes in operating assets and liabilities:
Real estate fund investments	(6,502)	(4,000)
Tenant and other receivables, net	(27,093)	(28,110)
Prepaid assets	(215,645)	(74,502)
Other assets	(41,328)	(10,195)
Accounts payable and accrued expenses	(4,058)	1,496
Other liabilities	(2,841)	(3,104)
Net cash provided by operating activities	191,360	397,971
Cash Flows from Investing Activities:
Proceeds from sale of condominium units at 220 Central Park South	939,292	1,039,493
Development costs and construction in progress	(448,167)	(448,281)
Moynihan Train Hall expenditures	(277,128)	(352,211)
Additions to real estate	(112,906)	(189,579)
Proceeds from sales of marketable securities	28,375	168,314
Investments in partially owned entities	(6,156)	(16,480)
Distributions of capital from partially owned entities	1,090	24,880
Acquisitions of real estate and other	(985)	(3,260)
Proceeds from transfer of interest in Fifth Avenue and Times Square JV (net of $35,562 of transaction costs and $10,899 of deconsolidated cash and restricted cash)	0	1,248,743
Proceeds from redemption of 640 Fifth Avenue preferred equity	0	500,000
Proceeds from sale of real estate and related investments	0	255,534
Proceeds from repayments of loans receivable	0	1,395
Net cash provided by investing activities	123,415	2,228,548
Cash Flows from Financing Activities:
Dividends paid on common shares / Distributions to Vornado	(725,938)	(377,750)
Proceeds from borrowings	555,918	1,107,852
Repayments of borrowings	(514,493)	(2,635,028)
Moynihan Train Hall reimbursement from Empire State Development	277,128	352,211
Contributions from noncontrolling interests / noncontrolling interests in consolidated subsidiaries	98,626	9,223
Distribution to noncontrolling interests / redeemable security holders and noncontrolling interests in consolidated subsidiaries	(76,759)	(65,084)
Dividends paid on preferred shares / Distributions to preferred unitholders	(50,123)	(37,598)
Proceeds received from exercise of employee share options (Vornado stock options) and other	5,567	2,403
Debt issuance costs	(1,357)	(15,328)
Repurchase of shares (Class A units) related to stock compensation arrangements and related tax withholdings	(137)	(8,692)
Purchase of marketable securities in connection with defeasance of mortgage payable	0	(407,126)
Prepayment penalty on redemption of senior unsecured notes due 2022	0	(22,058)
Redemption of preferred shares / units	0	(893)
Net cash used in financing activities	(431,568)	(2,097,868)
Net (decrease) increase in cash and cash equivalents and restricted cash	(116,793)	528,651
Cash and cash equivalents and restricted cash at beginning of period	1,607,131	716,905
Cash and cash equivalents and restricted cash at end of period	1,490,338	1,245,556
Reconciliation of Cash and Cash Equivalents and Restricted Cash:
Cash and cash equivalents at beginning of period	1,515,012	570,916
Restricted cash at beginning of period	92,119	145,989
Cash and cash equivalents and restricted cash at beginning of period	1,607,131	716,905
Cash and cash equivalents at end of period	1,411,047	1,132,491
Restricted cash at end of period	79,291	113,065
Cash and cash equivalents and restricted cash at end of period	1,490,338	1,245,556
Supplemental Disclosure of Cash Flow Information:
Cash payments for interest, excluding capitalized interest of $30,649 and $55,186	164,752	227,310
Cash payments for income taxes	14,252	47,345
Non-Cash Investing and Financing Activities:
Reclassification of condominium units from "development costs and construction in progress" to "220 Central Park South condominium units ready for sale"	370,850	825,520
Redeemable Class A unit measurement adjustment	272,436	123,635
Accrued capital expenditures included in accounts payable and accrued expenses	118,672	117,205
Write-off of fully depreciated assets	(111,863)	(113,261)
Investments received in exchange for transfer to Fifth Avenue and Times Square JV:
Preferred equity	0	2,327,750
Common equity	0	1,449,495
Lease liabilities arising from the recognition of right-of-use assets	0	526,866
Marketable securities transferred in connection with the defeasance of mortgage payable	0	(407,126)
Defeasance of mortgage payable	0	390,000
Amounts related to our investment in Pennsylvania Real Estate Investment Trust reclassified from "investments in partially owned entities" and "accumulated other comprehensive loss" to "marketable securities" upon conversion of operating partnership units to common shares	$ 0	$ 54,962