Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flows from Operating Activities:
Net (loss) income	$ (104,503)	$ 213,044
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Net unrealized loss (gain) on real estate fund investments	183,520	(100)
Depreciation and amortization (including amortization of deferred financing costs)	96,913	123,135
Net gains on disposition of wholly owned and partially owned assets	(68,589)	(220,294)
Distributions of income from partially owned entities	48,568	14,316
Stock-based compensation expense	25,765	31,654
Equity in net income of partially owned entities	(19,103)	(7,320)
Straight-lining of rents	10,165	1,140
Credit losses on loans receivable	7,261	0
Decrease (increase) in fair value of marketable securities	4,938	(461)
Amortization of below-market leases, net	(4,206)	(6,525)
Other non-cash adjustments	4,156	1,639
Changes in operating assets and liabilities:
Real estate fund investments	(6,000)	(4,000)
Tenant and other receivables, net	(20,938)	(835)
Prepaid assets	(91,878)	(82,862)
Other assets	(8,051)	(6,044)
Accounts payable and accrued expenses	(7,659)	10,426
Other liabilities	1,089	(2,795)
Net cash provided by operating activities	51,448	64,118
Cash Flows from Investing Activities:
Proceeds from sale of condominium units at 220 Central Park South	191,216	425,484
Development costs and construction in progress	(169,845)	(143,302)
Moynihan Train Hall expenditures	(98,794)	(123,533)
Additions to real estate	(49,251)	(55,759)
Proceeds from sales of marketable securities	28,375	167,755
Investments in partially owned entities	(2,130)	(918)
Distributions of capital from partially owned entities	1,090	24,851
Proceeds from sale of real estate and related investments	0	108,512
Proceeds from repayments of loans receivable	0	204
Net cash (used in) provided by investing activities	(99,339)	403,294
Cash Flows from Financing Activities:
Proceeds from borrowings	553,062	456,741
Dividends paid on common shares / Distributions to Vornado	(498,486)	(125,876)
Moynihan Train Hall reimbursement from Empire State Development	98,794	123,533
Distribution to noncontrolling interests / redeemable security holders and noncontrolling interests in consolidated subsidiaries	(40,045)	(16,252)
Dividends paid on preferred shares / Distributions to preferred unitholders	(12,531)	(12,534)
Proceeds received from exercise of employee share options (Vornado stock options) and other	4,899	1,511
Contributions from noncontrolling interests / noncontrolling interests in consolidated subsidiaries	4,786	5,194
Repayments of borrowings	(2,150)	(686,555)
Repurchase of shares (Class A units) related to stock compensation arrangements and related tax withholdings	(137)	(8,692)
Debt issuance costs	(124)	(10,860)
Redemption of preferred shares / units	0	(893)
Net cash provided by (used in) financing activities	108,068	(274,683)
Net increase (decrease) in cash and cash equivalents and restricted cash	60,177	192,729
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	1,667,308	909,634
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	1,586,738	307,047
Restricted cash at end of period	80,570	593,759
Restricted cash included in assets held for sale at end of period	0	8,828
Cash and cash equivalents and restricted cash at end of period	1,667,308	909,634
Supplemental Disclosure of Cash Flow Information:
Cash payments for interest, excluding capitalized interest of $11,913 and $21,371	53,997	85,796
Cash payments for income taxes	6,089	8,741
Non-Cash Investing and Financing Activities:
Adjustments to carry redeemable Class A units at redemption value	267,170	(65,818)
Reclassification of condominium units from development costs and construction in progress to 220 Central Park South condominium units ready for sale	106,479	395,893
Accrued capital expenditures included in accounts payable and accrued expenses	65,926	77,115
Write-off of fully depreciated assets	(45,115)	(58,309)
Reclassification of assets and related liabilities held for sale:
Assets held for sale	0	3,027,058
Liabilities related to assets held for sale	0	1,097,350
Lease liabilities arising from the recognition of right-of-use assets	0	526,866
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	0	54,962
Vornado Realty L.P.
Cash Flows from Operating Activities:
Net (loss) income	(104,503)	213,044
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Net unrealized loss (gain) on real estate fund investments	183,520	(100)
Depreciation and amortization (including amortization of deferred financing costs)	96,913	123,135
Net gains on disposition of wholly owned and partially owned assets	(68,589)	(220,294)
Distributions of income from partially owned entities	48,568	14,316
Stock-based compensation expense	25,765	31,654
Equity in net income of partially owned entities	(19,103)	(7,320)
Straight-lining of rents	10,165	1,140
Credit losses on loans receivable	7,261	0
Decrease (increase) in fair value of marketable securities	4,938	(461)
Amortization of below-market leases, net	(4,206)	(6,525)
Other non-cash adjustments	4,156	1,639
Changes in operating assets and liabilities:
Real estate fund investments	(6,000)	(4,000)
Tenant and other receivables, net	(20,938)	(835)
Prepaid assets	(91,878)	(82,862)
Other assets	(8,051)	(6,044)
Accounts payable and accrued expenses	(7,659)	10,426
Other liabilities	1,089	(2,795)
Net cash provided by operating activities	51,448	64,118
Cash Flows from Investing Activities:
Proceeds from sale of condominium units at 220 Central Park South	191,216	425,484
Development costs and construction in progress	(169,845)	(143,302)
Moynihan Train Hall expenditures	(98,794)	(123,533)
Additions to real estate	(49,251)	(55,759)
Proceeds from sales of marketable securities	28,375	167,755
Investments in partially owned entities	(2,130)	(918)
Distributions of capital from partially owned entities	1,090	24,851
Proceeds from sale of real estate and related investments	0	108,512
Proceeds from repayments of loans receivable	0	204
Net cash (used in) provided by investing activities	(99,339)	403,294
Cash Flows from Financing Activities:
Proceeds from borrowings	553,062	456,741
Dividends paid on common shares / Distributions to Vornado	(498,486)	(125,876)
Moynihan Train Hall reimbursement from Empire State Development	98,794	123,533
Distribution to noncontrolling interests / redeemable security holders and noncontrolling interests in consolidated subsidiaries	(40,045)	(16,252)
Dividends paid on preferred shares / Distributions to preferred unitholders	(12,531)	(12,534)
Proceeds received from exercise of employee share options (Vornado stock options) and other	4,899	1,511
Contributions from noncontrolling interests / noncontrolling interests in consolidated subsidiaries	4,786	5,194
Repayments of borrowings	(2,150)	(686,555)
Repurchase of shares (Class A units) related to stock compensation arrangements and related tax withholdings	(137)	(8,692)
Debt issuance costs	(124)	(10,860)
Redemption of preferred shares / units	0	(893)
Net cash provided by (used in) financing activities	108,068	(274,683)
Net increase (decrease) in cash and cash equivalents and restricted cash	60,177	192,729
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	1,667,308	909,634
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	1,586,738	307,047
Restricted cash at end of period	80,570	593,759
Restricted cash included in assets held for sale at end of period	0	8,828
Cash and cash equivalents and restricted cash at end of period	1,667,308	909,634
Supplemental Disclosure of Cash Flow Information:
Cash payments for interest, excluding capitalized interest of $11,913 and $21,371	53,997	85,796
Cash payments for income taxes	6,089	8,741
Non-Cash Investing and Financing Activities:
Adjustments to carry redeemable Class A units at redemption value	267,170	(65,818)
Reclassification of condominium units from development costs and construction in progress to 220 Central Park South condominium units ready for sale	106,479	395,893
Accrued capital expenditures included in accounts payable and accrued expenses	65,926	77,115
Write-off of fully depreciated assets	(45,115)	(58,309)
Reclassification of assets and related liabilities held for sale:
Assets held for sale	0	3,027,058
Liabilities related to assets held for sale	0	1,097,350
Lease liabilities arising from the recognition of right-of-use assets	0	526,866
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	$ 0	$ 54,962