Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities:
Net income	$ 210,577	$ 277,378
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization (including amortization of deferred financing costs)	407,539	446,040
Return of capital from real estate fund investments	80,294	71,888
Distributions of income from partially owned entities	65,097	56,853
Other non-cash adjustments	43,921	33,971
Straight-lining of rents	(37,752)	(118,798)
Amortization of below-market leases, net	(35,446)	(41,676)
Net realized and unrealized losses (gains) on real estate fund investments	18,537	(16,513)
Equity in net income of partially owned entities	(6,013)	(529)
Net gains on sale of real estate and other	(3,797)	(5,074)
Net gains on disposition of wholly owned and partially owned assets	(501)	(160,225)
Real estate impairment losses	0	161,165
Changes in operating assets and liabilities:
Tenant and other receivables, net	5,485	613
Prepaid assets	(70,949)	(58,998)
Other assets	(27,065)	(64,200)
Accounts payable and accrued expenses	27,609	4,793
Other liabilities	(15,911)	(14,274)
Net cash provided by operating activities	661,625	572,414
Cash Flows from Investing Activities:
Distributions of capital from partially owned entities	347,776	102,836
Development costs and construction in progress	(274,716)	(426,641)
Additions to real estate	(207,759)	(261,971)
Repayment of JBG SMITH Properties loan receivable	115,630	0
Investments in partially owned entities	(33,578)	(112,797)
Acquisitions of real estate and other	(11,841)	(91,100)
Proceeds from sales of real estate and related investments	9,543	167,673
Proceeds from repayments of mortgage loans receivable	650	33
Net deconsolidation of 7 West 34th Street	0	(48,000)
Investments in loans receivable and other	0	(11,700)
Purchases of marketable securities	0	(4,379)
Net cash used in investing activities	(54,295)	(686,046)
Cash Flows from Financing Activities:
Cash and cash equivalents and restricted cash included in the spin-off of JBG SMITH Properties ($275,000 plus The Bartlett financing proceeds less transaction costs and other mortgage items)	(416,237)	0
Dividends paid on common shares / Distributions to Vornado	(382,552)	(356,863)
Proceeds from borrowings	229,042	2,000,604
Repayments of borrowings	(177,109)	(1,591,554)
Dividends paid on preferred shares / Distributions to preferred unitholders	(48,386)	(64,006)
Distributions to noncontrolling interests / Distributions to redeemable security holders and noncontrolling interest in consolidated subsidiaries	(48,329)	(95,055)
Proceeds received from exercise of employee share options / Proceeds received from exercise of Vornado stock options	25,011	7,020
Debt issuance and other costs	(2,944)	(30,846)
Contributions from noncontrolling interests / noncontrolling interests in consolidated subsidiaries	1,044	11,900
Repurchase of shares / Class A units related to stock compensation agreements and related tax withholdings and other	(418)	(186)
Redemption of preferred shares / units	0	(246,250)
Net cash used in financing activities	(820,878)	(365,236)
Net decrease in cash and cash equivalents and restricted cash	(213,548)	(478,868)
Cash and cash equivalents and restricted cash at beginning of period	1,599,331	1,943,515
Cash and cash equivalents and restricted cash at end of period	1,385,783	1,464,647
Reconciliation of Cash and Cash Equivalents and Restricted Cash:
Cash and cash equivalents at beginning of period	1,501,027	1,835,707
Restricted cash at beginning of period	95,032	99,943
Restricted cash included in discontinued operations at beginning of period	3,272	7,865
Cash and cash equivalents and restricted cash at beginning of period	1,599,331	1,943,515
Cash and cash equivalents at end of period	1,282,230	1,352,697
Restricted cash at end of period	103,553	108,976
Restricted cash included in discontinued operations at end of period	0	2,974
Cash and cash equivalents and restricted cash at end of period	1,385,783	1,464,647
Supplemental Disclosure of Cash Flow Information:
Cash payments for interest, excluding capitalized interest of $31,243 and $21,297	257,173	275,979
Cash payments for income taxes	5,292	7,602
Non-cash distribution to JBG SMITH Properties:
Assets	3,432,738	0
Liabilities	(1,414,186)	0
Equity	(2,018,552)	0
Adjustments to carry redeemable Class A units at redemption value	286,928	(30,260)
Loan receivable established upon the spin-off of JBG SMITH Properties	115,630	0
Accrued capital expenditures included in accounts payable and accrued expenses	69,033	129,704
Write-off of fully depreciated assets	(41,458)	(283,496)
(Reduction) increase in unrealized net gain on available-for-sale securities	(10,559)	42,798
Decrease in assets and liabilities resulting from the deconsolidation of investments that were previously consolidated:
Real estate, net	0	(122,047)
Mortgage payable, net	0	(290,418)
Vornado Realty L.P.
Cash Flows from Operating Activities:
Net income	210,577	277,378
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization (including amortization of deferred financing costs)	407,539	446,040
Return of capital from real estate fund investments	80,294	71,888
Distributions of income from partially owned entities	65,097	56,853
Other non-cash adjustments	43,921	33,971
Straight-lining of rents	(37,752)	(118,798)
Amortization of below-market leases, net	(35,446)	(41,676)
Net realized and unrealized losses (gains) on real estate fund investments	18,537	(16,513)
Equity in net income of partially owned entities	(6,013)	(529)
Net gains on sale of real estate and other	(3,797)	(5,074)
Net gains on disposition of wholly owned and partially owned assets	(501)	(160,225)
Real estate impairment losses	0	161,165
Changes in operating assets and liabilities:
Tenant and other receivables, net	5,485	613
Prepaid assets	(70,949)	(58,998)
Other assets	(27,065)	(64,200)
Accounts payable and accrued expenses	27,609	4,793
Other liabilities	(15,911)	(14,274)
Net cash provided by operating activities	661,625	572,414
Cash Flows from Investing Activities:
Distributions of capital from partially owned entities	347,776	102,836
Development costs and construction in progress	(274,716)	(426,641)
Additions to real estate	(207,759)	(261,971)
Repayment of JBG SMITH Properties loan receivable	115,630	0
Investments in partially owned entities	(33,578)	(112,797)
Acquisitions of real estate and other	(11,841)	(91,100)
Proceeds from sales of real estate and related investments	9,543	167,673
Proceeds from repayments of mortgage loans receivable	650	33
Net deconsolidation of 7 West 34th Street	0	(48,000)
Investments in loans receivable and other	0	(11,700)
Purchases of marketable securities	0	(4,379)
Net cash used in investing activities	(54,295)	(686,046)
Cash Flows from Financing Activities:
Cash and cash equivalents and restricted cash included in the spin-off of JBG SMITH Properties ($275,000 plus The Bartlett financing proceeds less transaction costs and other mortgage items)	(416,237)	0
Dividends paid on common shares / Distributions to Vornado	(382,552)	(356,863)
Proceeds from borrowings	229,042	2,000,604
Repayments of borrowings	(177,109)	(1,591,554)
Dividends paid on preferred shares / Distributions to preferred unitholders	(48,386)	(64,006)
Distributions to noncontrolling interests / Distributions to redeemable security holders and noncontrolling interest in consolidated subsidiaries	(48,329)	(95,055)
Proceeds received from exercise of employee share options / Proceeds received from exercise of Vornado stock options	25,011	7,020
Debt issuance and other costs	(2,944)	(30,846)
Contributions from noncontrolling interests / noncontrolling interests in consolidated subsidiaries	1,044	11,900
Repurchase of shares / Class A units related to stock compensation agreements and related tax withholdings and other	(418)	(186)
Redemption of preferred shares / units	0	(246,250)
Net cash used in financing activities	(820,878)	(365,236)
Net decrease in cash and cash equivalents and restricted cash	(213,548)	(478,868)
Cash and cash equivalents and restricted cash at beginning of period	1,599,331	1,943,515
Cash and cash equivalents and restricted cash at end of period	1,385,783	1,464,647
Reconciliation of Cash and Cash Equivalents and Restricted Cash:
Cash and cash equivalents at beginning of period	1,501,027	1,835,707
Restricted cash at beginning of period	95,032	99,943
Restricted cash included in discontinued operations at beginning of period	3,272	7,865
Cash and cash equivalents and restricted cash at beginning of period	1,599,331	1,943,515
Cash and cash equivalents at end of period	1,282,230	1,352,697
Restricted cash at end of period	103,553	108,976
Restricted cash included in discontinued operations at end of period	0	2,974
Cash and cash equivalents and restricted cash at end of period	1,385,783	1,464,647
Supplemental Disclosure of Cash Flow Information:
Cash payments for interest, excluding capitalized interest of $31,243 and $21,297	257,173	275,979
Cash payments for income taxes	5,292	7,602
Non-cash distribution to JBG SMITH Properties:
Assets	3,432,738	0
Liabilities	(1,414,186)	0
Equity	(2,018,552)	0
Adjustments to carry redeemable Class A units at redemption value	286,928	(30,260)
Loan receivable established upon the spin-off of JBG SMITH Properties	115,630	0
Accrued capital expenditures included in accounts payable and accrued expenses	69,033	129,704
Write-off of fully depreciated assets	(41,458)	(283,496)
(Reduction) increase in unrealized net gain on available-for-sale securities	(10,559)	42,798
Decrease in assets and liabilities resulting from the deconsolidation of investments that were previously consolidated:
Real estate, net	0	(122,047)
Mortgage payable, net	$ 0	$ (290,418)