Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash Flows from Operating Activities:
Net income	$ 2,809,737	$ 105,620
Adjustments to reconcile net income to net cash provided by operating activities:
Net gain on transfer to Fifth Avenue and Times Square JV	(2,571,099)	0
Net gains on disposition of wholly owned and partially owned assets	(332,007)	(23,559)
Depreciation and amortization (including amortization of deferred financing costs)	240,866	233,748
Non-cash impairment loss on 608 Fifth Avenue right-of-use asset	75,220	0
Stock-based compensation expense	42,174	20,645
Distributions of income from partially owned entities	31,820	45,999
Equity in net (income) loss of partially owned entities	(30,193)	1,147
Real estate impairment losses	26,140	0
Prepayment penalty on redemption of senior unsecured notes due 2022	22,058	0
Net realized and unrealized loss on real estate fund investments	16,162	30,426
Amortization of below-market leases, net	(11,168)	(21,107)
Straight-lining of rents	3,733	(10,122)
(Increase) decrease in fair value of marketable securities	(1,773)	17,102
Return of capital from real estate fund investments	0	20,291
Other non-cash adjustments	18,588	3,675
Changes in operating assets and liabilities:
Real estate fund investments	(4,000)	(68,950)
Tenant and other receivables, net	(12,759)	(7,511)
Prepaid assets	(5,702)	(19,092)
Other assets	(8,498)	(114,881)
Accounts payable and accrued expenses	(11,482)	(11,036)
Other liabilities	(4,965)	38,865
Net cash provided by operating activities	292,852	241,260
Cash Flows from Investing Activities:
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)	1,255,756	0
Proceeds from sale of condominium units at 220 Central Park South	690,734	0
Proceeds from redemption of 640 Fifth Avenue preferred equity	500,000	0
Development costs and construction in progress	(289,532)	(185,039)
Moynihan Train Hall expenditures	(205,783)	0
Proceeds from sales of marketable securities	167,852	0
Additions to real estate	(120,060)	(113,300)
Proceeds from sale of real estate and related investments	108,512	44,599
Distributions of capital from partially owned entities	24,880	81,997
Investments in partially owned entities	(15,588)	(26,663)
Acquisitions of real estate and other	(3,260)	(56,500)
Net cash provided by (used in) investing activities	2,113,511	(254,906)
Cash Flows from Financing Activities:
Repayments of borrowings	(1,943,157)	(148,408)
Proceeds from borrowings	458,955	189,042
Purchase of marketable securities in connection with defeasance of mortgage payable	(407,126)	0
Dividends paid on common shares / Distributions to Vornado	(251,803)	(239,594)
Moynihan Train Hall reimbursement from Empire State Development	205,783	0
Distribution to noncontrolling interests / redeemable security holders and noncontrolling interests in consolidated subsidiaries	(49,140)	(49,338)
Dividends paid on preferred shares / Distributions to preferred unitholders	(25,066)	(30,047)
Prepayment penalty on redemption of senior unsecured notes due 2022	(22,058)	0
Debt issuance costs	(13,522)	(3,289)
Repurchase of shares (Class A units) related to stock compensation arrangements and related tax withholdings	(8,692)	(784)
Contributions from noncontrolling interests/ Distributions to redeemable security holders and noncontrolling interests in consolidated subsidiaries	8,315	59,558
Proceeds received from exercise of employee share options (Vornado stock options) and other	2,046	4,471
Redemption of preferred shares / units	(893)	(470,000)
Debt prepayment and extinguishment costs	0	(818)
Net cash used in financing activities	(2,046,358)	(689,207)
Net increase (decrease) in cash and cash equivalents and restricted cash	360,005	(702,853)
Cash and cash equivalents and restricted cash at beginning of period	716,905	1,914,812
Cash and cash equivalents and restricted cash at end of period	1,076,910	1,211,959
Reconciliation of Cash and Cash Equivalents and Restricted Cash:
Cash and cash equivalents at beginning of period	570,916	1,817,655
Restricted cash at beginning of period	145,989	97,157
Cash and cash equivalents and restricted cash at beginning of period	716,905	1,914,812
Cash and cash equivalents at end of period	922,604	1,090,791
Restricted cash at end of period	154,306	121,168
Cash and cash equivalents and restricted cash at end of period	1,076,910	1,211,959
Supplemental Disclosure of Cash Flow Information:
Cash payments for interest, excluding capitalized interest of $39,643 and $28,558	165,022	155,875
Cash payments for income taxes	28,697	4,365
Investments received in exchange for transfer to Fifth Avenue and Times Square JV:
Investments received in exchange for transfer to joint venture, preferred equity	2,327,750	0
Investments received in exchange for transfer to joint venture, common equity	1,449,495	0
Reclassification of condominium units from development costs and construction in progress to 220 Central Park South condominium units ready for sale	647,683	0
Lease liabilities arising from the recognition of right-of-use assets	526,866	0
Marketable securities transferred in connection with the defeasance of mortgage payable	(407,126)	0
Defeasance of mortgage payable	390,000	0
Adjustments to carry redeemable Class A units at redemption value	99,407	36,450
Write-off of fully depreciated assets	(93,390)	(38,117)
Accrued capital expenditures included in accounts payable and accrued expenses	68,900	54,176
Amounts related to our investment in Pennsylvania Real Estate Investment Trust reclassified from investments in partially owned entities and accumulated other comprehensive (loss) income to marketable securities upon conversion of operating partnership units to common shares	54,962	0
Vornado Realty L.P.
Cash Flows from Operating Activities:
Net income	2,809,737	105,620
Adjustments to reconcile net income to net cash provided by operating activities:
Net gain on transfer to Fifth Avenue and Times Square JV	(2,571,099)	0
Net gains on disposition of wholly owned and partially owned assets	(332,007)	(23,559)
Depreciation and amortization (including amortization of deferred financing costs)	240,866	233,748
Non-cash impairment loss on 608 Fifth Avenue right-of-use asset	75,220	0
Stock-based compensation expense	42,174	20,645
Distributions of income from partially owned entities	31,820	45,999
Equity in net (income) loss of partially owned entities	(30,193)	1,147
Real estate impairment losses	26,140	0
Prepayment penalty on redemption of senior unsecured notes due 2022	22,058	0
Net realized and unrealized loss on real estate fund investments	16,162	30,426
Amortization of below-market leases, net	(11,168)	(21,107)
Straight-lining of rents	3,733	(10,122)
(Increase) decrease in fair value of marketable securities	(1,773)	17,102
Return of capital from real estate fund investments	0	20,291
Other non-cash adjustments	18,588	3,675
Changes in operating assets and liabilities:
Real estate fund investments	(4,000)	(68,950)
Tenant and other receivables, net	(12,759)	(7,511)
Prepaid assets	(5,702)	(19,092)
Other assets	(8,498)	(114,881)
Accounts payable and accrued expenses	(11,482)	(11,036)
Other liabilities	(4,965)	38,865
Net cash provided by operating activities	292,852	241,260
Cash Flows from Investing Activities:
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)	1,255,756	0
Proceeds from sale of condominium units at 220 Central Park South	690,734	0
Proceeds from redemption of 640 Fifth Avenue preferred equity	500,000	0
Development costs and construction in progress	(289,532)	(185,039)
Moynihan Train Hall expenditures	(205,783)	0
Proceeds from sales of marketable securities	167,852	0
Additions to real estate	(120,060)	(113,300)
Proceeds from sale of real estate and related investments	108,512	44,599
Distributions of capital from partially owned entities	24,880	81,997
Investments in partially owned entities	(15,588)	(26,663)
Acquisitions of real estate and other	(3,260)	(56,500)
Net cash provided by (used in) investing activities	2,113,511	(254,906)
Cash Flows from Financing Activities:
Repayments of borrowings	(1,943,157)	(148,408)
Proceeds from borrowings	458,955	189,042
Purchase of marketable securities in connection with defeasance of mortgage payable	(407,126)	0
Dividends paid on common shares / Distributions to Vornado	(251,803)	(239,594)
Moynihan Train Hall reimbursement from Empire State Development	205,783	0
Distribution to noncontrolling interests / redeemable security holders and noncontrolling interests in consolidated subsidiaries	(49,140)	(49,338)
Dividends paid on preferred shares / Distributions to preferred unitholders	(25,066)	(30,047)
Prepayment penalty on redemption of senior unsecured notes due 2022	(22,058)	0
Debt issuance costs	(13,522)	(3,289)
Repurchase of shares (Class A units) related to stock compensation arrangements and related tax withholdings	(8,692)	(784)
Contributions from noncontrolling interests/ Distributions to redeemable security holders and noncontrolling interests in consolidated subsidiaries	8,315	59,558
Proceeds received from exercise of employee share options (Vornado stock options) and other	2,046	4,471
Redemption of preferred shares / units	(893)	(470,000)
Debt prepayment and extinguishment costs	0	(818)
Net cash used in financing activities	(2,046,358)	(689,207)
Net increase (decrease) in cash and cash equivalents and restricted cash	360,005	(702,853)
Cash and cash equivalents and restricted cash at beginning of period	716,905	1,914,812
Cash and cash equivalents and restricted cash at end of period	1,076,910	1,211,959
Reconciliation of Cash and Cash Equivalents and Restricted Cash:
Cash and cash equivalents at beginning of period	570,916	1,817,655
Restricted cash at beginning of period	145,989	97,157
Cash and cash equivalents and restricted cash at beginning of period	716,905	1,914,812
Cash and cash equivalents at end of period	922,604	1,090,791
Restricted cash at end of period	154,306	121,168
Cash and cash equivalents and restricted cash at end of period	1,076,910	1,211,959
Supplemental Disclosure of Cash Flow Information:
Cash payments for interest, excluding capitalized interest of $39,643 and $28,558	165,022	155,875
Cash payments for income taxes	28,697	4,365
Investments received in exchange for transfer to Fifth Avenue and Times Square JV:
Investments received in exchange for transfer to joint venture, preferred equity	2,327,750	0
Investments received in exchange for transfer to joint venture, common equity	1,449,495	0
Reclassification of condominium units from development costs and construction in progress to 220 Central Park South condominium units ready for sale	647,683	0
Lease liabilities arising from the recognition of right-of-use assets	526,866	0
Marketable securities transferred in connection with the defeasance of mortgage payable	(407,126)	0
Defeasance of mortgage payable	390,000	0
Adjustments to carry redeemable Class A units at redemption value	99,407	36,450
Write-off of fully depreciated assets	(93,390)	(38,117)
Accrued capital expenditures included in accounts payable and accrued expenses	68,900	54,176
Amounts related to our investment in Pennsylvania Real Estate Investment Trust reclassified from investments in partially owned entities and accumulated other comprehensive (loss) income to marketable securities upon conversion of operating partnership units to common shares	$ 54,962	$ 0