Fair Value Disclosures [Abstract] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Recurring Fair Value, Recurring [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 3 Fair Value, Inputs, Level 3 [Member] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Real estate fund investments Real Estate Funds [Member] Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Number of investments held by fund Number Of Investments Held By Fund Number Of Investments Held By Fund during the year. Real estate fund investments Real Estate Fund Nondepreciable Real Estate This element represents the real estate assets related to the fund Excess of fair value below cost Investment Owned Unrecognized Unrealized Appreciation Value The amount of excess fair value of investments over it's cost. Real Estate Real Estate [Member] Fair Value, Measurements, Nonrecurring Fair Value, Nonrecurring [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Real estate assets Assets, Fair Value Disclosure Income Statement [Abstract] Statement [Table] Statement [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Rental revenues Rental Revenue [Member] Rental Revenue [Member] Fee and other income Fee And Other Income [Member] Fee And Other Income [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Vornado Realty L.P. Vornado Realty L.P. [Member] Statement [Line Items] Statement [Line Items] REVENUES: Revenues [Abstract] Total revenues Revenues EXPENSES: Operating Expenses [Abstract] Operating Operating Costs and Expenses Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction General and administrative General and Administrative Expense (Expense) benefit from deferred compensation plan liability Mark-to-market Expense (Benefit) of Investments in Deferred Compensation Plan Mark-to-market Expense (Benefit) of Investments in Deferred Compensation Plan Transaction related costs, impairment losses and other Transaction Related Costs, Impairment Losses and Other Transaction Related Costs, Impairment Losses and Other Total expenses Operating Expenses Income from partially owned entities Income Loss From Equity Method Investments Including Fees Earned (Loss) income from real estate fund investments Income (loss) from real estate fund investments This element represents the income (loss) from the Real Estate Fund before allocation to noncontrolling interests Interest and other investment income, net Interest and other investment (loss) income, net This element represents interest and other investment loss income net of tax incuding impairment losses, mark-to-market adjustments for derivatives or mark-to-market investments in deferred compensation. Income (loss) from deferred compensation plan assets Gain Loss of investments in deferred compensation plan Gain Loss of investments in deferred compensation plan Interest and debt expense Interest and Debt Expense Net gain on transfer to Fifth Avenue and Times Square JV Gain (Loss) on Transfer Of Interest In Properties To Real Estate Investments, Joint Ventures Gain (Loss) on Transfer Of Interest In Properties To Real Estate Investments, Joint Ventures Purchase price fair value adjustment Gain (Loss) Representing Purchasing Price Fair Value Adjustment Gain (Loss) Representing Purchasing Price Fair Value Adjustment Net gains on disposition of wholly owned and partially owned assets Gain (Loss) on Disposition of Assets Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) Income from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest (Loss) income from discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Less net loss (income) attributable to noncontrolling interests in: Net Income (Loss) Attributable to Noncontrolling Interest [Abstract] Consolidated subsidiaries Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Nonredeemable Operating Partnership Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Net income attributable to Vornado / Vornado Realty L.P. Net Income (Loss) Attributable to Parent Preferred share dividends / unit distributions Preferred Stock Dividends, Income Statement Impact Preferred share / unit issuance costs Preferred Stock Redemption Premium NET INCOME attributable to common shareholders / Class A unitholders Net Income (Loss) Available to Common Stockholders, Basic INCOME PER COMMON SHARE - BASIC: Earnings Per Share, Basic [Abstract] Income from continuing operations, net (in dollars per share) Income (Loss) from Continuing Operations, Per Basic Share Loss from discontinued operations, net (in dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share Net income per common share (in dollars per share) Earnings Per Share, Basic Weighted average shares outstanding Weighted Average Number of Shares Outstanding, Basic INCOME PER COMMON SHARE - DILUTED: Earnings Per Share, Diluted [Abstract] Income from continuing operations, net (in dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Loss from discontinued operations, net (in dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share Net income per common share (in dollars per share) Earnings Per Share, Diluted Weighted average shares outstanding Weighted Average Number of Shares Outstanding, Diluted INCOME PER CLASS A UNIT - BASIC: Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax [Abstract] Income from continuing operations, net (in dollars per share) Income (Loss) from Continuing Operations, Per Outstanding Limited Partnership Unit, Basic, Net of Tax Income (loss) from discontinued operations, net (in dollars per share) Income (Loss) from Discontinued Operations, Net of Tax, Per Outstanding Limited Partnership Unit, Basic Net income per Class A unit (in dollars per share) Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax Weighted average units outstanding Weighted Average Limited Partnership Units Outstanding, Basic INCOME PER CLASS A UNIT - DILUTED: Net Income (Loss), Net of Tax, Per Outstanding Limited Partnership Unit, Diluted [Abstract] Income from continuing operations, net (in dollars per share) Income (Loss) from Continuing Operations, Net of Tax, Per Outstanding Limited Partnership Unit, Diluted Loss from discontinued operations, net (in dollars per share) Income (Loss) from Discontinued Operations, Net of Tax, Per Outstanding Limited Partnership Unit, Diluted Net income per Class A unit (in dollars per share) Net Income (Loss), Net of Tax, Per Outstanding Limited Partnership Unit, Diluted Weighted average units outstanding Weighted Average Limited Partnership Units Outstanding, Diluted Equity Method Investments and Joint Ventures [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Maturing in January 2026 Maturing in January 2026 [Member] Maturing in January 2026 [Member] Maturing in 2021 Maturing in 2021 [Member] Maturing in 2021 [Member] Matures in June 2023 Matures in June 2023 [Member] Matures in June 2023 [Member] Matures in 2019 Matures in 2019 [Member] Matures in 2019 [Member] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Office and Retail Property Office and Retail Property [Member] Office and Retail Property [Member] Office Building Office Building [Member] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] 512 West 22nd Street Five One Two West 22nd Street [Member] Five One Two West 22nd Street [Member] 61 9th Avenue Sixty One 9th Avenue [Member] Sixty One 9th Avenue [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Joint Venture Corporate Joint Venture [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Urban Edge Properties Urban Edge Properties [Member] The name of the new company created during spin off. Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Equity method ownership percentage Equity Method Investment, Ownership Percentage Loans repaid Loans Payable Square footage of real estate property (in sqft) Area of Real Estate Property Spread Over LIBOR (in percentage) Debt Instrument, Basis Spread on Variable Rate Debt instrument, interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Debt proceeds, net Proceeds from (Repayments of) Debt Shares sold (shares) Equity Method Investment, Shares Sold Equity Method Investment, Shares Sold Proceeds from sale of equity method investments Proceeds from Sale of Equity Method Investments Gain (loss) on sale of equity investments Gain (Loss) on Sale of Equity Investments Debt term (years) Debt Instrument, Term Length of extension available (years) Length Of Extension Available The term of the extension available, in years Accounting Policies [Abstract] Non cash impairment losses Equity Method Investment, Other than Temporary Impairment Share-based Payment Arrangement [Abstract] Stock-based Compensation Share-based Payment Arrangement [Text Block] Cover page. Entities [Table] Entities [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Shares of beneficial interest, $.04 par value per share Common Stock [Member] 5.70% Series K Series K Preferred Stock [Member] 5.40% Series L Series L Preferred Stock [Member] 5.40% Series L Cumulative Redeemable Preferred Stock [Member] 5.25% Series M Series M Preferred Stock [Member] Series M Preferred Stock [Member] Entity Listings, Exchange [Axis] Entity Listings, Exchange [Axis] Exchange [Domain] Exchange [Domain] New York Stock Exchange NEW YORK STOCK EXCHANGE, INC. [Member] Entity Information [Line Items] Entity Information [Line Items] Document Type Document Type Document Transition Report Document Transition Report Document Annual Report Document Annual Report Document Period End Date Document Period End Date Entity Registrant Name Entity Registrant Name Entity File Number Entity File Number Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line One Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Title of 12(g) Security Title of 12(g) Security Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Shell Company Entity Shell Company Entity Public Float Entity Public Float Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Entity Central Index Key Entity Central Index Key Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Current Fiscal Year End Date Current Fiscal Year End Date Redeemable Noncontrolling Interest, Equity, Carrying Amount [Abstract] Fair value of Series G convertible preferred units and Series D-13 cumulative redeemable preferred units Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Fair Value of Shares Intangible Assets, Net (Excluding Goodwill) [Abstract] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Below Market Leases Net Of Above Market Leases Below Market Leases Net Of Above Market Leases [Member] Below Market Leases Net Of Above Market Leases [Member] Other Identified Intangible Assets Other Identified Intangible Assets [Member] Other Identified Intangible Assets [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] 2020 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2023 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2024 Finite-Lived Intangible Assets, Amortization Expense, Year Five Interest and Other Income [Abstract] Schedule of interest and other investment income (loss), net Interest and Other Income [Table Text Block] Investments in Partially Owned Entities Equity Method Investments and Joint Ventures Disclosure [Text Block] Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility Revolving Credit Facility [Member] 606 Broadway Six Zero Six Broadway [Member] Property on 606 Broadway. Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Cap Interest Rate Cap [Member] Retail Retail Site [Member] Office Space Office Space [Member] Office Space [Member] 435 Seventh Avenue Four Three Five Seventh Avenue [Member] Four Three Five Seventh Avenue [Member] 100 West 33rd Street One Hundred West 33rd Street [Member] One Hundred West 33rd Street [Member] 888 Seventh Avenue Eight Eight Eight Seventh Avenue [Member] New York Office 888 Seventh Avenue [Member] PENN2 PENN2 [Member] PENN2 [Member] Maturing in February 2024 Maturing in February 2024 [Member] Maturing in February 2024 [Member] Maturing in August 2019 Maturing in August 2019 [Member] Maturing in August 2019 [Member] Maturing in April 2024 Maturing in April 2024 [Member] Maturing in April 2024 [Member] Maturing in July 2020 Maturing in July 2020 [Member] Maturing in July 2020 [Member] Maturing in December 2025 Maturing in December 2025 [Member] Maturing in December 2025 [Member] Fixed Through December 2020 Fixed Through December 2020 [Member] Fixed Through December 2020 [Member] Matures in 2024 Matures in 2024 [Member] Matures in 2024 [Member] Matures in 2021 Matures in 2021 [Member] Matures in 2021 [Member] Matures in December 2021 Matures in December 2021 [Member] Matures in December 2021 [Member] Senior Unsecured Notes Due 2022 Senior Unsecured Notes Due 2022 [Member] Senior Unsecured Notes Due 2022 [Member] Maturing in March 2024 Maturing in March 2024 [Member] Maturing in March 2024 [Member] Maturing in February 2022 Maturing in February 2022 [Member] Maturing in February 2022 [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior Unsecured Notes Senior Unsecured Notes [Member] Senior Unsecured Notes [Member] Line of Credit Line of Credit [Member] Debt Instrument Debt Instrument [Line Items] Refinancing Square footage of real estate property (in sqft) Debt instrument, interest rate, effective percentage Debt Instrument, Interest Rate, Effective Percentage Repayments of debt Proceeds from Debt, Net of Issuance Costs Number of extensions (extension) Number of Extensions Number of Extensions Repayments of loan Repayments of Debt Debt instrument, redeemed Debt Instrument, Repurchased Face Amount Debt instrument, redemption price, percentage Debt Instrument, Redemption Price, Percentage Charge related to prepayment and unamortized financing costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Unsecured revolving credit facilities Long-term Line of Credit Number of revolving credit facility Number Of Revolving Credit Facility Number Of Revolving Credit Facility Facility fee, percentage Line of Credit Facility, Commitment Fee Percentage Real Estate Fund Investments [Abstract] Investment Holdings [Table] Investment Holdings [Table] One Park Avenue One Park Avenue [Member] One Park Avenue Investment Holdings Investment Holdings [Line Items] Details Of Income From Real Estate Funds Details Of Income From Real Estate Funds [Abstract] Net investment income Net Investment Income Net unrealized loss on held investments Unrealized Gain (Loss) on Investments Net realized (loss) gain on exited investments Gain (Loss) on Sale of Investments Previously recorded unrealized gain on exited investment Previously Recorded Unrealized Gains On Exited Investments This element represents previously recorded unrealized gains on exited investments. New York City real property transfer tax (the Transfer Tax) Real Estate Transfer Tax Paid Real Estate Transfer Tax Paid Loss (income) from real estate fund investments Less loss (income) attributable to noncontrolling interests in consolidated subsidiaries Loss from real estate fund investments net of controlling interests in consolidated subsidiaries(2) Net Income (Loss) from Real Estate Investment Partnership Leases [Abstract] Accounts Receivable, Allowance for Credit Loss [Roll Forward] Accounts Receivable, Allowance for Credit Loss [Roll Forward] Balance at Beginning of Year Accounts Receivable, Allowance for Credit Loss Additions Charged Against Operations Accounts Receivable, Credit Loss Expense (Reversal) Uncollectible Accounts Written-off Accounts Receivable, Allowance for Credit Loss, Writeoff Balance at End of Year Statement of Stockholders' Equity [Abstract] Common shares/units, dividends (in dollars per share) Common Stock, Dividends, Per Share, Declared Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Real estate, at cost: Real Estate Investment Property, at Cost [Abstract] Land Land Buildings and improvements Buildings and Improvements, Gross Development costs and construction in progress Development in Process Moynihan Train Hall development expenditures Development Expenditures Development Expenditures Leasehold improvements and equipment Fixtures and Equipment, Gross Total Real Estate Investment Property, at Cost Less accumulated depreciation and amortization Real Estate Investment Property, Accumulated Depreciation Real estate, net Real Estate Investment Property, Net Right-of-use assets Operating Lease, Right-of-Use Asset Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents Marketable securities Marketable Securities Tenant and other receivables Accounts Receivable, after Allowance for Credit Loss Investments in partially owned entities Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures 220 Central Park South condominium units ready for sale Real Estate Held-for-sale Receivable arising from the straight-lining of rents Deferred Rent Receivables, Net Deferred leasing costs, net of accumulated amortization of $196,229 and $207,529 Deferred Leasing And Financing Costs Net Of Accumulated Amortization This element represents costs incurred by the lessor that are (a) costs to originate a lease incurred in transactions with independent third parties that (i) result directly from and are essential to acquire that lease and (ii) would not have been incurred had that leasing transaction not occurred and (b) certain costs directly related to specified activities performed by the lessor for that lease. Those activities are: evaluating the prospective lessee's financial condition; evaluating and recording guarantees, collateral, and other security arrangements; negotiating lease terms; preparing and processing lease documents; and closing the transaction. This element is net of accumulated amortization, combined with, for an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain. Identified intangible assets, net of accumulated amortization of $98,587 and $172,114 Finite-Lived Intangible Assets, Net Other assets Other Assets Assets Assets LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY Liabilities and Equity [Abstract] Mortgages payable, net Notes and Loans Payable Senior unsecured notes, net Unsecured Debt Unsecured term loan, net Unsecured Long-term Debt, Noncurrent Lease liabilities Operating Lease, Liability Moynihan Train Hall obligation Financing Obligation Financing Obligation Special dividend/distribution payable on January 15, 2020 Dividends Payable Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities Deferred revenue Contract with Customer, Liability Deferred compensation plan Deferred Compensation Liability, Current and Noncurrent Other liabilities Other Liabilities Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies Redeemable noncontrolling interests / partnership units: Class A units - 13,298,956 and 12,544,477 units outstanding Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount Series D cumulative redeemable preferred units - 141,401 and 177,101 units outstanding Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount Total redeemable noncontrolling interests / partnership units Redeemable Noncontrolling Interest, Equity, Carrying Amount Shareholders' / Partners' equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred shares of beneficial interest: no par value per share; authorized 110,000,000 shares; issued and outstanding 36,795,640 and 36,798,580 shares Preferred Stock, Value, Issued Common shares of beneficial interest: $0.04 par value per share; authorized 250,000,000 shares; issued and outstanding 190,985,677 and 190,535,499 shares Common Stock, Value, Issued Additional capital Additional Paid in Capital Partners' capital General Partners' Capital Account Earnings less than distributions Retained Earnings (Accumulated Deficit) Accumulated other comprehensive (loss) income Accumulated Other Comprehensive Income (Loss), Net of Tax Total Vornado and Vornado Realty L.P. shareholders' equity Stockholders' Equity Attributable to Parent Noncontrolling interests in consolidated subsidiaries Stockholders' Equity Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities, redeemable noncontrolling interests / partnership units and equity Liabilities and Equity SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, by Property [Table] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, by Property [Table] Major Property Class [Axis] Major Property Class [Axis] Major Property Class [Domain] Major Property Class [Domain] Land Land [Member] Buildings & improvements Building Improvements [Member] Real Estate And Accumulated Depreciation SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward] Real estate, balance at beginning of period Additions during the period SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Other Addition Less: Assets sold, written-off and deconsolidated SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Cost of Investment in Real Estate Sold Real estate, balance at end of period SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward] Accumulated depreciation, balance at beginning of period SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation Additions charged to operating expenses SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation, Depreciation Expense Real estate accumulated depreciation Real Estate Accumulated Depreciation Before Accumulated Depreciation On Asset Sold And Written Off The subtotal of accumulated depreciation balance excluding accumulated depreciation on assets sold and write-off of accumulated depreciation on fully depreciated assets. Less: Accumulated depreciation on assets sold, written-off and deconsolidated SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation, Investment in Real Estate Sold Accumulated depreciation, balance at end of period Transaction Related Costs, Impairment Losses and Other [Abstract] Transaction Related Costs, Impairment Losses and Other [Abstract] Transaction Related Costs, Impairment Losses and Other [Table] Transaction Related Costs, Impairment Losses and Other [Table] Transaction Related Costs, Impairment Losses and Other [Table] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Valuation Technique, Discounted Cash Flow Valuation Technique, Discounted Cash Flow [Member] 608 Fifth Avenue Six Zero Eight Fifth Avenue [Member] Six Zero Eight Fifth Avenue [Member] Transaction Related Costs, Impairment Losses and Other [Line Items] Transaction Related Costs, Impairment Losses and Other [Line Items] [Line Items] for Transaction Related Costs, Impairment Losses and Other [Table] Real estate, measurement input Other Real Estate Owned, Measurement Input Non-cash impairment loss and related write-offs Asset Impairment Charges Operating lease, impairment loss Operating Lease, Impairment Loss Equity [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Conversion Feature [Axis] Conversion Feature [Axis] Conversion Feature [Domain] Conversion Feature [Domain] Redeemable Preferred Stock Redeemable Preferred Stock [Member] Capital Units by Class [Axis] Capital Units by Class [Axis] Capital Unit, Class [Domain] Capital Unit, Class [Domain] Class A Capital Unit, Class A [Member] Class of Stock [Line Items] Class of Stock [Line Items] Common Stock Number Of Shares Par Value And Other Disclosures Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Common shares / Class A units of beneficial interest: outstanding shares Common Stock, Shares, Outstanding Dividends / Distributions paid on common shares / Class A units Payments of Ordinary Dividends, Common Stock Dividends per common share (usd per share) Dividends Payable, Amount Per Share Dividends Payable, Date to be Paid Dividends Payable, Date to be Paid Dividends Payable, Date Declared Dividends Payable, Date Declared Payments of special dividend Payments of Special Dividend, Common Stock Payments of Special Dividend, Common Stock Outstanding Partnership Units held by Third Parties Temporary Equity, Shares Outstanding Preferred Stock, Number of Shares, Par Value and Other Disclosures Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Preferred dividends Payments of Ordinary Dividends, Preferred Stock and Preference Stock Preferred stock, redemption price per share (in usd per share) Preferred Stock, Redemption Price Per Share Preferred stock, liquidation preference per share Preferred Stock, Liquidation Preference Per Share Interest and Debt Expense [Abstract] Interest expense Interest Costs Incurred Capitalized interest and debt expense Interest Costs Capitalized Adjustment This element represents Capitalized interest and debt expenses amount. Amortization of deferred financing costs Amortization of Debt Issuance Costs Interest and debt expense Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Loss Contingencies [Table] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Subsidiary of Regus PLC Subsidiary of Regus PLC [Member] Subsidiary of Regus PLC [Member] 345 Montgomery Street Three Four FIve Montgomery Street [Member] Three Four FIve Montgomery Street [Member] Farley Office and Retail Building Farley Office and Retail Building [Member] Farley Office and Retail Building [Member] PPIC PPIC [Member] Penn Plaza Insurance Company', our wholly owned consolidated subsidiary, is acting as re-insurance with respect to a portion of earthquake insurance coverage and insurance with respect to coverage for acts of terrorism as defined by TRIPRA. Regus PLC Regus PLC [Member] Regus PLC [Member] Insurance Coverage Type Name [Axis] Insurance Coverage Type Name [Axis] Insurance Coverage Type Name [Domain] Insurance Coverage Type Name [Domain] General Liability General Liability [Member] All Risk And Rental Value All Risk And Rental Value [Member] Amount of all risk and rental value insurance coverage against damages to property. Earthquake California Properties Earthquake California Properties [Member] Amount of insurance coverage against damages to property caused by earthquakes in California. Terrorism Acts Terrorism Acts [Member] Terrorism Acts [Member] Non-Certified Acts of Terrorism Non-Certified Acts of Terrorism [Member] Non-Certified Acts of Terrorism [Member] NBCR NBCR [Member] Amount of insurance coverage against damages to property caused by acts of terrorism including nuclear, biological, chemical and radiological acts as defined by TRIA. Property and Development Activities Property and Development Activities [Member] Property and Development Activities [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Insurance Insurance [Abstract] Insurance limit per property Insurance Limit Per Property Insurance limit per property. Insurance limit per occurrence Insurance Limit Per Occurrence Insurance Limit Per Occurrence Vornado deductible, percentage of property value Registrant Deductible Percentage Of Property Value Vornado deductible, percentage of property value Insurance maximum coverage limit in aggregate Insurance Maximum Coverage In Aggregate Insurance maximum coverage limit in aggregate. Insurance deductible Insurance deductible Insurance deductible Insurance deductible percentage of balance of covered loss Insurance Deductible Percentage Of Balance Of Covered Loss Insurance deductible, percentage of balance of a covered loss Other Commitments Other Commitments [Abstract] Lessor, lease not yet commenced, term of contract (years) Lessor, Operating Lease, Lease Not yet Commenced, Term of Contract Contractual obligation (up to) Guarantor Obligations, Maximum Exposure, Undiscounted Guarantees and master leases Guarantees And Master Leases Guarantees And Master Leases Outstanding letters of credit Letters of Credit Outstanding, Amount Commitment to fund additional capital to partially owned entities Commitment To Fund Additional Capital To Partially Owned Entities Commitment To Fund Additional Capital To Partially Owned Entities Other commitment Other Commitment Schedule of Debt Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Maturities of Long-Term Debt Schedule of Maturities of Long-term Debt [Table Text Block] Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2020 Operating Leases, Future Minimum Payments, Due in Two Years 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Investors Investors [Member] Investors [Member] Vornado Realty Trust Vornado Realty Trust [Member] Vornado Realty Trust Matures in 2022 Matures in 2022 [Member] Matures in 2022 [Member] Maturing in September 2019 Maturing in September 2019 [Member] Maturing in September 2019 [Member] Matures in December 2029 Matures in December 2029 [Member] Matures in December 2029 [Member] Matures in October 2020 Matures in October 2020 [Member] Matures in October 2020 [Member] Matures in December 2024 Matures in December 2024 [Member] Matures in December 2024 [Member] Matures in August 2020 Matures in August 2020 [Member] Matures in August 2020 [Member] Residential Properties Residential Properties [Member] Residential Property [Member] 825 Seventh Avenue Eight Two Five Seventh Avenue [Member] Eight Two Five Seventh Avenue [Member] 330 Madison Avenue Three Three Zero Madison Avenue [Member] 650 Madison Avenue Six FIve Zero Madison Avenue [Member] Six FIve Zero Madison Avenue [Member] 50-70 West 93rd Street 50-70 West 93rd Street [Member] 50-70 West 93rd Street [Member] Toys R Us Toys R Us [Member] Toys R Us [Member] Fifth Avenue and Times Square JV Fifth Avenue and Times Square JV [Member] Fifth Avenue and Times Square JV [Member] Schedule of Equity Method Investments [Line Items] Realized gain on disposal Equity Method Investment, Realized Gain (Loss) on Disposal Total equity method investment Equity Method Investment, Aggregate Cost Tax basis of investments, cost for income tax purposes Tax Basis of Investments, Cost for Income Tax Purposes Equity method investment, effective ownership transferred percentage Equity Method Investment, Effective Ownership Transferred Percentage Equity Method Investment, Effective Ownership Transferred Percentage Number of units (units) Number of Units Number of Units Interest And Debt Expense Interest And Debt Expense [Text Block] This disclosure relates to the details of interest and debt expense of the company. The interest expense relates to secured and unsecured debt of the company Debt Instrument Redemption [Table] Debt Instrument Redemption [Table] Debt Instrument, Redemption [Line Items] Debt Instrument, Redemption [Line Items] Multiemployer Plans [Abstract] Schedule of Multiemployer Plans [Table] Schedule of Multiemployer Plans [Table] Multiemployer Plan Type [Axis] Multiemployer Plan Type [Axis] Multiemployer Plans Type [Domain] Multiemployer Plans Type [Domain] Multiemployer Pension Plans Multiemployer Plans, Pension [Member] Multiemployer Health Plans Multiemployer Plans, Healthcare Benefit [Member] Multiemployer Benefit Plans Multiemployer Plans [Line Items] Multiemployer plan, period contributions Multiemployer Plan, Contributions by Employer Multiemployer plans contributions represent more than 5% of total employer contributions Multiemployer Plans, Period Contributions, Significance of Contributions [true false] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] OP Units Out Performance Units [Member] Out Performance Units [Member] Performance Conditioned AO LTIP Units Performance Conditioned AO LTIP Units [Member] Performance Conditioned AO LTIP Units [Member] AO LTIP Units AO LTIP Units [Member] AO LTIP Units [Member] OPPs Out Performance Plan [Member] Out Performance Plan. Vornado restricted stock Restricted Stock [Member] Vornado stock options Share-based Payment Arrangement, Option [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based compensation expense Share-based Payment Arrangement, Expense Interest and Other Investment Income, Net Investment Income [Table Text Block] Earnings Per Share [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities Excluded From Computation Of Earnings Per Share Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Weighted average common share equivalents of excluded dilutive securities due to anti-dilutive effect Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Equity Method Investments Equity Method Investments [Table Text Block] Related Party Transactions [Abstract] Affiliated Entity [Abstract] Affiliated Entity [Abstract] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Title of Individual [Axis] Title of Individual [Axis] Title of Individual [Domain] Title of Individual [Domain] Director Director [Member] 220 Central Park South Two Two Zero Central Park South Site [Member] New York Manhattan 220 Central Park South Site [Member] Alexanders Inc Alexanders Inc [Member] Alexanders Inc Interstate Properties Interstate Properties [Member] Interstate Properties [Member] Immediate Family Member of Management or Principal Owner Immediate Family Member of Management or Principal Owner [Member] Investor Investor [Member] Related Party Transaction Related Party Transaction [Line Items] Percentage of affiliated entity owned by company Percentage of Affiliated Entity Owned By Company Percentage of Alexanders Owned By Company Percentage of company owned by related party Percentage of Company Owned by Related Party his element represents the percentage of the company owned by related party Percentage of affiliated entity owned by related parties Percentage Of Affiliated Entity Owned By Related Parties Percentage Of Affiliated Entity Owned By Related Parties Related party transaction annual fee percentage Property Management Fee, Percent Fee Term of management agreement Term Of Management Agreement Renewal Term Of Management Agreement Period allowed for termination of automatic renewal of management agreement Period Allowed For Termination Of Automatic Renewal Of Management Agreement Maximum Period Allowed For Termination Of Automatic Renewal Of Management Agreement Fee and other income from related parties (in US dollars) Property Management Fee Revenue Cash proceeds from sale of real estate Proceeds from Sale of Real Estate Revenue from Contract with Customer [Abstract] Revenue Recognition Revenue from Contract with Customer [Text Block] Equity Method Investments And Income From Equity Method Investments Equity Method Investments And Income From Equity Method Investments [Abstract] This abstract relates to equity method investments and income from equity method investments Investment owned, balance, shares Investment Owned, Balance, Shares Amount Alexander owed Accounts Receivable, Related Parties Closing share price (in dollars per share) Sale of Stock, Price Per Share Equity method investment, quoted market value Equity Method Investment, Quoted Market Value Excess of investee's fair value over carrying amount Equity Method Investment Fair Value In Excess Of Carrying Amount Equity Method Investment Fair Value In Excess Of Carrying Amount Excess of investee's carrying amount over equity in net assets Equity Method Investment, Difference Between Carrying Amount and Underlying Equity Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Real Estate Properties [Table] Schedule of Real Estate Properties [Table] Ownership [Axis] Ownership [Axis] Ownership [Domain] Ownership [Domain] Operating Partnership Operating Partnership [Member] Operating Partnership [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] New York New York Segment [Member] Domain member used to indicate facts reported for the New York Office Segment. Other Other Segment [Member] Other Member including eliminations, non-core business related activities. Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Manhattan Manhattan [Member] New York City Metropolitan Area New York City Metropolitan Area [Member] Domain member used to indicate facts reported for the New York Office Segment. Chicago Chicago [Member] Domain member used to indicate facts reported for the continuing operations in Chicago San Francisco San Francisco [Member] Hotel Pennsylvania Hotel Pennsylvania [Member] Domain member used to indicate facts reported for the continuing operations of Hotel Pennsylvania. Lexington Avenue 731 Lexington Avenue 731 [Member] the Mart, Chicago Merchandise Mart Chicago [Member] Merchandise Mart Merchandise Mart [Member] 555 California Street Five Five Five California Street [Member] Domain member used to indicate facts reported for the continuing operations of 555 California Street. Real Estate Properties Real Estate Properties [Line Items] Common limited partnership interest in the Operating Partnership Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest Number of real estate properties Number of Real Estate Properties Number of units in real estate property (in number of residential units) Number of Units in Real Estate Property Number of buildings Number of Buildings Number of Buildings Statement of Comprehensive Income [Abstract] Net income Other comprehensive (loss) income: Other Comprehensive Income (Loss), Net of Tax [Abstract] (Reduction) increase in value of interest rate swaps and other Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges And Other, Net of Tax Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges And Other, Net of Tax Amounts reclassified from accumulated other comprehensive (loss) income relating to nonconsolidated subsidiaries Other Comprehensive Income (Loss), Pro Rata Share of Nonconsolidated Subsidiaries Other Comprehensive Income (Loss), Pro Rata Share of Nonconsolidated Subsidiaries Other comprehensive (loss) income of nonconsolidated subsidiaries Our Share Of Partially Owned Entities Oci Adjustments This element represents the company's pro-rata share of other comprehensive income (loss) adjustments related to non-consolidated subsidiaries Reduction in unrealized net gain on available-for-sale securities Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Less comprehensive (income) loss attributable to noncontrolling interests in consolidated subsidiaries Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to Vornado Comprehensive Income (Loss), Net of Tax, Attributable to Parent Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Deferred Compensation Plan Assets Deferred Compensation Plan Assets [Member] Deferred Compensation Plan Assets Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Beginning balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Net unrealized loss on held investments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Unrealized Gain (Loss) Included In Earnings This element represents Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Realized Gain (Loss) Included In Earnings. Purchases/additional fundings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Dispositions/sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Net realized loss on exited investments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Realized Gain (Loss) Included In Earnings This element represents Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Realized Gain (Loss) Included In Earnings. Realized and unrealized gains (losses) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Realized And Unrealized Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Realized And Unrealized Other, net Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Other Net Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Other Gain Loss Net Ending balance Gross amount Finite-Lived Intangible Assets, Gross Accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Identified intangible liabilities (included in deferred revenue): Identified Intangible Liabilities [Abstract] Identified Intangible Liabilities [Abstract] Gross amount Finite Lived Intangible Liability Gross This element represents the identifiable intangible liability established upon acquisition based on an unfavorable difference between the terms of an acquired lease and the current market terms for that lease at the acquisition date. Accumulated amortization Finite Lived Intangible Liability Accumulated Amortization The accumulated amount of amortization of a major finite-lived intangible liability class. A major class is composed of intangible liabilities that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. Net Finite Lived Intangible Liabilities Net The aggregate sum of gross carrying value of a major finite-lived intangible liabilty class, less accumulated amortization. A major class is composed of intangible liabilities that can be grouped together because they are similar, either by their nature or by their use in the operations of a company Derivative [Table] Derivative [Table] Interest Rate Swap Interest Rate Swap [Member] 770 Broadway mortgage loan Seven Seventy Broadway Mortgage Loan [Member] Seven Seventy Broadway Mortgage Loan [Member] 888 Seventh Avenue mortgage loan Eight Eight Eight Seventh Avenue Mortgage Loan [Member] Eight Eight Eight Seventh Avenue Mortgage Loan [Member] Other Other Debt [Member] Other Debt [Member] Unsecured term loan Senior Unsecured Term Loan [Member] Senior Unsecured Term Loan [Member] 33-00 Northern Boulevard mortgage loan Three Three - Zero Zero Northern Boulevard Mortgage Loan [Member] Three Three - Zero Zero Northern Boulevard Mortgage Loan [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Assets Other Assets [Member] Other Liabilities Other Liabilities [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Derivative [Line Items] Derivative [Line Items] Derivative Asset, Fair Value Derivative Asset, Fair Value, Gross Asset Derivative Asset, Notional Amount Derivative Asset, Notional Amount Derivative Liability, Fair Value Derivative Liability, Fair Value, Gross Liability Derivative Liability, Notional Amount Derivative Liability, Notional Amount Derivative, Average Basis Spread on Variable Rate Derivative, Basis Spread on Variable Rate Derivative, Interest Rate Derivative, Variable Interest Rate Derivative, Swap Rate Derivative, Fixed Interest Rate Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Total AOCI Attributable to Parent [Member] Accumulated other comprehensive income of nonconsolidated subsidiaries Pro Rata Share Of Non Consolidated Subsidiaries Oci [Member] Pro-rata share of non consolidated subsidiaries' OCI Interest rate swaps Accumulated Gain (Loss), Net, Cash Flow Hedge, Noncontrolling Interest [Member] Other Other Changes In Accumulated Comprehensive Income Loss [Member] Other Changes In Accumulated Comprehensive Income Loss [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance, value Other comprehensive (loss) income Other Comprehensive Income (Loss), Net of Tax Amount reclassified from accumulated other comprehensive income Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Ending balance, value Mortgages Mortgages [Member] Unsecured Debt Unsecured Debt [Member] Unsecured Revolving Credit Facilities Unsecured Revolving Credit Facilities [Member] Unsecured Revolving Credit Facilities [Member] Rate Type [Axis] Rate Type [Axis] Rate Type [Axis] Rate Type [Domain] Rate Type [Domain] Rate Type [Domain] Fixed Rate Fixed Rate [Member] Fixed Rate [Member] Variable Rate Variable Rate [Member] Variable Rate [Member] Mortgages payable, gross Notes And Loans Payable Gross Notes And Loans Payable Gross Deferred financing costs, net and other Debt Issuance Costs, Net Total, net Unsecured debt, gross Unsecured Debt, Gross Unsecured Debt, Gross Unsecured debt, net Unsecured term loan, net Revolving credit facilities Long-term debt Long-term Debt Interest rate, end of period (in percentage) Collateral property, net carrying value Collateral Property Net Carrying Value The net carrying value of property collateralizing the notes and mortgages payable Schedule of Transaction Related Costs, Impairment Losses and Other Schedule of Transaction Related Costs, Impairment Losses and Other [Table Text Block] Schedule of Transaction Related Costs, Impairment Losses and Other [Table Text Block] Schedule III Real Estate and Accumulated Depreciation SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Operating expenses NOI - consolidated Net Operating Income (Loss) Cash Basis, Consolidated Net Operating Income (Loss) Cash Basis, Consolidated Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries Net Operating Income (Loss), Portion Attributable to Noncontrolling Interest, Total Net Operating Income (Loss), Portion Attributable to Noncontrolling Interest, Total Add: Our share of NOI from partially owned entities Net Operating Income (Loss) from Equity Method Investments Net Operating Income (Loss) from Equity Method Investments NOI at share Operating Income Loss Cash Basis Represents cash basis of Net Operating Income which is before allocation to the noncontrolling interest of the Operating Partnership. Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net and other Straightline rents and other Adjustments Amount of the non cash adjustment to straight-line rents, amortization of acquired below-market leases, net and other. NOI at share - cash basis Cash Basis Property-Level NOI Cash Basis Property-Level NOI Balance Sheet Data: Balance Sheet Data [Abstract] Real estate, at cost Number of reportable segments (segment) Number of Reportable Segments Shareholders' Equity/Partners' Capital Stockholders' Equity Note Disclosure [Text Block] 7 West 34th Street Seven West 34th Street [Member] New York 7 West 34th Street [Member] 85 Tenth Avenue Eight Five Tenth Avenue [Member] Eight Five Tenth Avenue [Member] Partially Owned Office Buildings Partially owned office buildings [Member] Partially Owned Office Buildings PREIT Pennsylvania Real Estate Investment Trust [Member] Pennsylvania Real Estate Investment Trust UE Other investments Other equity method investments [Member] Other equity method investments Carrying amount of investments in partially owned entities Carrying amount of investments in partially owned entities Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Liabilities Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Liabilities Discontinued Operations and Disposal Groups [Abstract] Dispositions Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Illinois ILLINOIS New York NEW YORK Maryland MARYLAND New Jersey NEW JERSEY California CALIFORNIA 1290 Avenue of the Americas One Two Nine Zero Avenue Of Americas [Member] New York Office 1290 Avenue Of The Americas [Member] 350 Park Avenue Three Five Zero Park Avenue [Member] New York 350 Park Avenue [Member] PENN1 One Penn Plaza [Member] New York Office One Penn Plaza [Member] 100 West 33rd Street Hundred West 33rd Street [Member] New York Office 100 West 33rd Street [Member] 150 West 34th Street One Five Zero West 34th Street [Member] 150 West 34th Street property. PENN2 Two Penn Plaza New York Office Two Penn Plaza [Member] 90 Park Avenue Ninety Park Avenue [Member] New York Office 90 Park Avenue [Member] Manhattan Mall Manhattan Mall [Member] New York Office Manhattan Mall [Member] 770 Broadway Seven Seven Zero Broadway [Member] New York Office 770 Broadway [Member] PENN11 Eleven Penn Plaza [Member] New York Office Eleven Penn Plaza [Member] 909 Third Avenue Nine Zero Nine Third Avenue [Member] New York Office 909 Third Avenue [Member] 150 East 58th Street One Five Zero East 58th Street [Member] New York Office 150 East 58th Street [Member] 595 Madison Avenue Five Nine Five Madison Avenue [Member] New York Office 595 Madison Avenue [Member] 330 West 34th Street Three Three Zero West 34th Street [Member] New York Office 330 West 34th Street [Member] 828 To 850 Madison Avenue Eight Two Eight To 850 Madison Avenue [Member] Eight Two Eight To 850 Madison Avenue [Member] 715 Lexington Avenue Lexington Avenue 715 Retail [Member] Lexington Avenue 715 Retail [Member] 478 To 486 Broadway Four Seven Eight To 486 Broadway [Member] New York Office 478 To 486 Broadway [Member] 4 Union Square South Four Union Square South [Member] 4 Union Square South [Member] Farley Office and Retail Building Moynihan Office Building [Member] Moynihan Office Building [Member] Moynihan Train Hall Moynihan Train Hall [Member] Moynihan Train Hall [Member] 260 11th Avenue Two Sixty Eleventh Avenue [Member] Property located at 260 11th Avenue, New York. 510 5th Avenue Five One Zero 5th Avenue [Member] New York 510 5th Avenue - Retail [Member] 40 Fulton Street Forty Fulton Street [Member] New York Office 40 Fulton Street [Member] 443 Broadway Four Four Three Broadway [Member] New York Office 443 Broadway [Member] 40 East 66th Street Forty East 66th Street [Member] New York Office 40 East 66th Street [Member] 155 Spring Street One Five Five Spring Street [Member] New York Office 155 Spring Street [Member] 435 7th Avenue Four Three Five 7th Avenue [Member] New York Office 435 7th Avenue [Member] 692 Broadway Six Nine Two Broadway [Member] New York Office 692 Broadway [Member] 131-135 West 33rd Street One Three One to One Three Five West Thirty Three [Member] 265 West 34th Street Two Sixty Five West 34th Street [Member] Property located at Two Sixty Five West 34th Street. 304 Canal Street Three Zero Four Canal Street [Member] New York Office 304 Canal Street [Member] 677 To 679 Madison Avenue Six Seven Seven To 679 Madison Avenue [Member] New York Office 677 To 679 Madison Avenue [Member] 1131 Third Avenue One One Three One Third Avenue [Member] One One Three One Third Avenue [Member] 486 Eighth Avenue Four Eight Six Eighth Avenue [Member] 431 Seventh Avenue Four Three One 7th Avenue [Member] New York Office 431 7th Avenue 138-142 West 32nd Street One Three Eight - 142 West 32nd Street [Member] One Three Eight - 142 West 32nd Street Property. 334 Canal Street Three Three Four Canal Street [Member] New York Office 334 Canal Street [Member] 267 West 34th Street Two Six Seven West 34th Street [Member] New York Office 267 West 34 Street [Member] 966 Third Avenue Nine Six Six Third Avenue [Member] New York Office 966 Third Avenue [Member] 148 Spring Street One Four Eight Spring Street [Member] New York Office 148 Spring Street [Member] 150 Spring Street One Fifty Spring Street [Member] New York Office 150 Spring Street [Member] 137 West 33rd Street One Three Seven West 33rd Street [Member] One Three Seven West 33rd Street property. 488 Eighth Avenue Four Eight Eight 8th Avenue [Member] New York Office 488 8th Avenue [Member] 484 Eighth Avenue Four Eight Four 8th Avenue [Member] New York Office 484 8th Avenue [Member] 825 7th Avenue Eight Two Five 7th Avenue [Member] New York Office 825 7th Avenue [Member] 537 West 26th Street Five Three Seven West 26th Street [Member] Five Three Seven West 26th Street [Member] 339 Greenwich Three Three Nine Greenwich [Member] Three Three Nine Greenwich [Member] Other (Including Signage) Other Including Signage [Member] New York Office Other Including Signage [Member] 33-00 Northern Boulevard Three Three - Zero Zero Northern Boulevard [Member] 33-00 Northern Boulevard property. Paramus Paramus [Member] Hotel Pennsylvania/Paramus Hotel Pennsylvania/Paramus [Member] Hotel Pennsylvania/Paramus [Member] 527 West Kinzie, Chicago Merchandise Mart IL 527 W. Kinzie, Chicago [Member] Merchandise Mart IL 527 W. Kinzie, Chicago [Member] Piers 92 and 94 Piers 92 and 94 [Member] Piers 92 and 94 [Member] Total The Mart Total Merchandise Mart [Member] Merchandise Mart Total Merchandise Mart [Member] Borgata Land, Atlantic City, NJ Borgata Land [Member] Other Properties Atlantic City NJ [Member] 40 East 66th Residential Forty East 66th Residential [Member] Other Properties 40 East 66th Residential [Member] 677-679 Madison Six Seven Seven 679 Madison [Member] Other Properties 677-679 Madison [Member] Annapolis Annapolis [Member] Annapolis [Member] Wayne Towne Center Wayne Towne Center [Member] Wayne Towne Center [Member] Other Property Other Property [Member] Leasehold Improvements Equipment and Other Leasehold Improvements Equipment and Other [Member] Leasehold Improvements Equipment and Other [Member] Encumbrances SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances Initial cost to company SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost [Abstract] Land SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land Buildings and improvements SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements Costs capitalized subsequent to acquisition SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Improvements Gross amount at which carried at close of period SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross [Abstract] Land SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount Buildings and improvements SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount Total SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross Accumulated depreciation and amortization Date of construction Real Estate And Accumulated Depreciation Year Of Construction Date acquired Real Estate And Accumulated Depreciation Year Of Acquisition Net basis difference of assets and liabilities between tax basis and GAAP basis Net Basis Difference Of Assets And Liabilities Between Tax Basis And GAAP Basis Net Basis Difference Of Assets And Liabilities Between Tax Basis And GAAP Basis Real estate and accumulated depreciation life used for depreciation SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation Quarterly Financial Information Disclosure [Abstract] Quarterly Financial Data [Table] Quarterly Financial Data [Table] Quarterly Financial Data Quarterly Financial Data [Line Items] Schedule Of Quarterly Financial Information Quarterly Financial Information [Table Text Block] Investment Income [Table] Investment Income [Table] Lexington Realty Trust Lexington Realty Trust [Member] Lexington Realty Trust [Member] Other Other [Member] Other [Member] Mezzanine Loan Mezzanine Loan [Member] Mezzanine Loan [Member] Net Investment Income [Line Items] Net Investment Income [Line Items] (Decrease) increase in fair value of marketable securities Marketable Securities, Unrealized Gain (Loss) Interest on cash and cash equivalents and restricted cash Interest on Cash and Cash Equivalents and Restricted Cash Interest on Cash and Cash Equivalents and Restricted Cash Interest on loans receivable Interest and Fee Income, Loans and Leases Dividends on marketable securities Investment Income, Dividend Other, net Other Nonoperating Income (Expense) Interest and other investment income, net Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] 3040 M Street 3040 M Street [Member] 3040 M Street [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Dispositions Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract] Cash proceeds from sale of real estate Net gains on sale of real estate and other Gain (Loss) on Sale of Properties Tax gain Gain (Loss) on Sale of Properties, Net Gain (Loss) on Sale of Properties, Net Schedule Of Other Share Based Compensation, Activity Share-based Payment Arrangement, Outstanding Award, Activity, Excluding Option [Table Text Block] Schedule of Unrecognized Compensation Expense Share-based Payment Arrangement, Nonvested Award, Cost [Table Text Block] Schedule Of Share Based Compensation Restricted Operating Partnership Units Earned Schedule Of Sharebased Compensation Restricted Operating Partnership Units Earned [Table Text Block] Schedule Of Sharebased Compensation Restricted Operating Partnership Units Earned [Table Text Block] Schedule Of Share Based Compensation Stock Options Activity Share-based Payment Arrangement, Option, Activity [Table Text Block] Schedule Of Share Based Payment Award Stock Options Valuation Assumptions Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule Of Share Based Compensation Restricted Operating Partnership Units Activity Schedule Of Sharebased Compensation Restricted Operating Partnership Units Activity [Table Text Block] For restricted operating partnership units, disclosure of the number and weighted-average grant date fair value for restricted operating partnership units that were outstanding at the beginning and end of the year, and the number of restricted operating partnership units that were granted, vested, or forfeited during the year. Schedule Of Share Based Compensation Restricted Stock And Restricted Stock Units Activity Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Income Per Share / Income Per Class A Unit Earnings Per Share [Text Block] Fair value, schedule of assets and liabilities measures on recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Fair value inputs quantitative information Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Summary of changes in level 3 plan assets Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair value measurements, nonrecurring Fair Value Measurements, Nonrecurring [Table Text Block] Schedule of carrying amounts and fair values of financial instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule of Derivative Assets at Fair Value Schedule of Derivative Assets at Fair Value [Table Text Block] Schedule of Derivative Liabilities at Fair Value Schedule of Derivative Liabilities at Fair Value [Table Text Block] Restricted Cash Restricted Cash [Member] Restricted Cash [Member] Deferred compensation plan assets Deferred Compensation Plan Assets Interest rate swaps (included in other assets) Interest Rate Derivative Assets, at Fair Value Total assets Mandatorily redeemable instruments (included in other liabilities) Mandatorily Redeemable Preferred Stock, Fair Value Disclosure Interest rate swaps (included in other liabilities) Interest Rate Derivative Liabilities, at Fair Value Total liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Marketable Securities [Abstract] Unrealized Gain (Loss) on Investments Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Senior Unsecured Debt And Unsecured Revolving Credit Facilities Senior Unsecured Debt And Unsecured Revolving Credit Facilities [Member] Senior Unsecured Debt And Unsecured Revolving Credit Facilities Member. Contractual Obligation, Fiscal Year Maturity Schedule [Abstract] Contractual Obligation, Fiscal Year Maturity Schedule [Abstract] 2020 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2021 Long-term Debt, Maturities, Repayments of Principal in Year Two 2022 Long-term Debt, Maturities, Repayments of Principal in Year Three 2023 Long-term Debt, Maturities, Repayments of Principal in Year Four 2024 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Share Based Compensation Employee Stock Purchase Plan Activity Share Based Compensation Employee Stock Purchase Plan Activity [Abstract] Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Options outstanding at beginning of period (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Exercised (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Vested (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period Cancelled or expired (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Options outstanding at end of period (shares) Options vested and expected to vest at end of period (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Option exercisable at end of period (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted- Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Options outstanding at beginning of period (in usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted (in usd per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Exercised (in usd per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Vested (in usd per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Vested in Period, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Vested in Period, Weighted Average Exercise Price Cancelled or expired (in usd per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Options outstanding at end of period (in usd per share) Options vested and expected to vest at end of period (in usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Options exercisable at end of period (in usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Weighted- Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Options outstanding, Weighted Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Options vested and expected to vest, Weighted Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term Options exercisable, Weighted Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Aggregate Intrinsic Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Aggregate Intrinsic Value [Abstract] Options outstanding, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Options vested and expected to vest, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value Options exercisable, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract] Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract] 2020 Lessor, Operating Lease, Payments to be Received, Next Twelve Months 2021 Lessor, Operating Lease, Payments to be Received, Two Years