Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Basis of Presentation and Significant Accounting Policies
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of Vornado and the Operating Partnership and their consolidated subsidiaries. All inter-company amounts have been eliminated. Our consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”), which require us to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
Recently Issued Accounting Literature	Recently Issued Accounting Literature In May 2014, the Financial Accounting Standards Board (“FASB”) issued an update ("ASU 2014-09") establishing Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC 606”). ASU 2014-09 establishes a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most of the existing revenue recognition guidance. ASU 2014-09 requires an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and also requires certain additional disclosures. In August 2015, the FASB issued an update (“ASU 2015-14”) to ASC 606, Deferral of the Effective Date, which defers the adoption of ASU 2014-09 to interim and annual reporting periods in fiscal years that begin after December 15, 2017. In March 2016, the FASB issued an update (“ASU 2016-08”) to ASC 606, Principal versus Agent Considerations (Reporting Revenue Gross versus Net), which clarifies the implementation guidance on principal versus agent considerations in the new revenue recognition standard pursuant to ASU 2014-09. In April 2016, the FASB issued an update (“ASU 2016-10”) to ASC 606, Identifying Performance Obligations and Licensing, which clarifies guidance related to identifying performance obligations and licensing implementation guidance contained in ASU 2014-09. In May 2016, the FASB issued an update (“ASU 2016-12”) to ASC 606, Narrow-Scope Improvements and Practical Expedients, which amends certain aspects of the new revenue recognition standard pursuant to ASU 2014-09. We are permitted to use either the retrospective or the modified retrospective method when adopting these standards. We are evaluating the impact of the adoption of these standards on our consolidated financial statements and have not yet concluded on the method of adoption. In June 2014, the FASB issued an update (“ASU 2014-12”) to ASC Topic 718, Compensation – Stock Compensation (“ASC 718”). ASU 2014-12 requires an entity to treat performance targets that can be met after the requisite service period of a share based award has ended, as a performance condition that affects vesting. ASU 2014-12 is effective for interim and annual reporting periods in fiscal years that began after December 15, 2015. The adoption of this update as of January 1, 2016, did not have any impact on our consolidated financial statements. In February 2015, the FASB issued an update (“ASU 2015-02”) Amendments to the Consolidation Analysis to ASC Topic 810, Consolidation. ASU 2015-02 affects reporting entities that are required to evaluate whether they should consolidate certain legal entities. Specifically, the amendments: (i) modify the evaluation of whether limited partnerships and similar legal entities are variable interest entities ("VIEs") or voting interest entities, (ii) eliminate the presumption that a general partner should consolidate a limited partnership, (iii) affect the consolidation analysis of reporting entities that are involved with VIEs, and (iv) provide a scope exception for certain entities. ASU 2015-02 is effective for interim and annual reporting periods beginning after December 15, 2015. The adoption of this update on January 1, 2016 resulted in the identification of additional VIEs, but did not have an impact on our consolidated financial statements other than additional disclosures (see Note 11 - Variable Interest Entities). In January 2016, the FASB issued an update (“ASU 2016-01”) Recognition and Measurement of Financial Assets and Financial Liabilities to ASC Topic 825, Financial Instruments. ASU 2016-01 amends certain aspects of recognition, measurement, presentation and disclosure of financial instruments, including the requirement to measure certain equity investments at fair value with changes in fair value recognized in net income. ASU 2016-01 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. We are currently evaluating the impact of the adoption of ASU 2016-01 on our consolidated financial statements. In February 2016, the FASB issued (“ASU 2016-02”) Leases, which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessees and lessors. ASU 2016-02 requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase. Lessees are required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. Lessees will recognize expense based on the effective interest method for finance leases or on a straight-line basis for operating leases. ASU 2016-02 will more significantly impact the accounting for leases in which we are a lessee. We have a number of ground leases for which we will be required to record a right-of-use asset and lease liability upon adoption of this standard. ASU 2016-02 is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. We are currently evaluating the impact of the adoption of ASU 2016-02 on our consolidated financial statements, including the timing of adopting this standard. In March 2016, the FASB issued an update (“ASU 2016-09”) Improvements to Employee Share-Based Payment Accounting to ASC 718. ASU 2016-09 amends several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2016. We are currently evaluating the impact of the adoption of ASU 2016-09 on our consolidated financial statements. In August 2016, the FASB issued an update (“ASU 2016-15”) Classification of Certain Cash Receipts and Cash Payments to ASC Topic 230, Statement of Cash Flows. ASU 2016-15 clarifies guidance on the classification of certain cash receipts and payments in the statement of cash flows to reduce diversity in practice with respect to (i) debt prepayment or debt extinguishment costs, (ii) settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, (iii) contingent consideration payments made after a business combination, (iv) proceeds from the settlement of insurance claims, (v) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies, (vi) distributions received from equity method investees, (vii) beneficial interests in securitization transactions, and (viii) separately identifiable cash flows and application of the predominance principle. ASU 2016-15 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. The adoption of this update is not expected to have a significant impact on our consolidated financial statements. In November 2016, the FASB issued an update (“ASU 2016-18”) Restricted Cash to ASC Topic 230, Statement of Cash Flows. ASU 2016-18 requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Restricted cash and restricted cash equivalents will be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period balances on the statement of cash flows upon adoption of this standard. ASU 2016-18 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. In January 2017, the FASB issued an update (“ASU 2017-01”) Clarifying the Definition of a Business to ASC Topic 805, Business Combinations. ASU 2017-01 provides a screen to determine when an asset acquired or group of assets acquired is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated. ASU 2017-01 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. We have elected to early adopt this standard, effective as of October 1, 2016, for all future acquisitions. The adoption of this standard will result in less real estate acquisitions qualifying as businesses and, accordingly, acquisition costs for those acquisitions that are not businesses will be capitalized rather than expensed. There was no impact of the adoption of this standard in the fourth quarter of 2016, as there have been no acquisitions.
Real Estate	Real Estate: Real estate is carried at cost, net of accumulated depreciation and amortization. Betterments, major renewals and certain costs directly related to the improvement and leasing of real estate are capitalized. Maintenance and repairs are expensed as incurred. For redevelopment of existing operating properties, the net book value of the existing property under redevelopment plus the cost for the construction and improvements incurred in connection with the redevelopment are capitalized to the extent the capitalized costs of the property do not exceed the estimated fair value of the redeveloped property when complete. If the cost of the redeveloped property, including the net book value of the existing property, exceeds the estimated fair value of redeveloped property, the excess is charged to expense. Depreciation is recognized on a straight-line basis over estimated useful lives which range from 7 to 40 years. Tenant allowances are amortized on a straight-line basis over the lives of the related leases, which approximate the useful lives of the assets. Additions to real estate include interest and debt expense capitalized during construction of $34,097,000 and $59,305,000 for the years ended December 31, 2016 and 2015, respectively. Upon the acquisition of real estate that meets the criteria of a business under ASU 2017-01, we assess the fair value of acquired assets (including land, buildings and improvements, identified intangibles, such as acquired above and below-market leases, acquired in-place leases and tenant relationships) and acquired liabilities and we allocate the purchase price based on these assessments. We assess fair value based on estimated cash flow projections that utilize appropriate discount and capitalization rates and available market information. Estimates of future cash flows are based on a number of factors including historical operating results, known trends, and market/economic conditions. We record acquired intangible assets (including acquired above-market leases, acquired in-place leases and tenant relationships) and acquired intangible liabilities (including below–market leases) at their estimated fair value separate and apart from goodwill. We amortize identified intangibles that have finite lives over the period they are expected to contribute directly or indirectly to the future cash flows of the property or business acquired. Our properties, including any related intangible assets, are individually reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. An impairment exists when the carrying amount of an asset exceeds the aggregate projected future cash flows over the anticipated holding period on an undiscounted basis. An impairment loss is measured based on the excess of the property’s carrying amount over its estimated fair value. Impairment analyses are based on our current plans, intended holding periods and available market information at the time the analyses are prepared. If our estimates of the projected future cash flows, anticipated holding periods, or market conditions change, our evaluation of impairment losses may be different and such differences could be material to our consolidated financial statements. The evaluation of anticipated cash flows is subjective and is based, in part, on assumptions regarding future occupancy, rental rates and capital requirements that could differ materially from actual results. Plans to hold properties over longer periods decrease the likelihood of recording impairment losses.
Partially Owned Entities	Partially Owned Entities: We consolidate entities in which we have a controlling financial interest. In determining whether we have a controlling financial interest in a partially owned entity and the requirement to consolidate the accounts of that entity, we consider factors such as ownership interest, board representation, management representation, authority to make decisions, and contractual and substantive participating rights of the partners/members as well as whether the entity is a variable interest entity (“VIE”) and whether we are the primary beneficiary. We are deemed to be the primary beneficiary of a VIE when we have (i) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (ii) the obligation to absorb losses or receive benefits that could potentially be significant to the VIE. We generally do not control a partially owned entity if the entity is not considered a VIE and the approval of all of the partners/members is contractually required with respect to major decisions, such as operating and capital budgets, the sale, exchange or other disposition of real property, the hiring of a chief executive officer, the commencement, compromise or settlement of any lawsuit, legal proceeding or arbitration or the placement of new or additional financing secured by assets of the venture. We account for investments under the equity method when the requirements for consolidation are not met, and we have significant influence over the operations of the investee. Equity method investments are initially recorded at cost and subsequently adjusted for our share of net income or loss and cash contributions and distributions each period. Investments that do not qualify for consolidation or equity method accounting are accounted for on the cost method. Investments in partially owned entities are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. An impairment loss is measured based on the excess of the carrying amount of an investment over its estimated fair value. Impairment analyses are based on current plans, intended holding periods and available information at the time the analyses are prepared. In the years ended December 31, 2016, 2015 and 2014, we recognized non-cash impairment losses on investments in partially owned entities aggregating $20,290,000, $21,260,000 and $85,459,000, respectively. Included in 2014 is a $75,196,000 impairment loss related to our investment in Toys.
Cash And Cash Equivalents	Cash and Cash Equivalents: Cash and cash equivalents consist of highly liquid investments with original maturities of three months or less and are carried at cost, which approximates fair value due to their short-term maturities. The majority of our cash and cash equivalents consists of (i) deposits at major commercial banks, which may at times exceed the Federal Deposit Insurance Corporation limit, (ii) United States Treasury Bills, and (iii) Certificate of Deposits placed through an Account Registry Service (“CDARS”). To date, we have not experienced any losses on our invested cash.
Restricted Cash	Restricted Cash: Restricted cash consists of security deposits, cash restricted for the purposes of facilitating a Section 1031 Like-Kind exchange, cash restricted in connection with our deferred compensation plan and cash escrowed under loan agreements for debt service, real estate taxes, property insurance and capital improvements.
Allowance For Doubtful Accounts	Allowance for Doubtful Accounts: We periodically evaluate the collectability of amounts due from tenants and maintain an allowance for doubtful accounts for estimated losses resulting from the inability of tenants to make required payments under the lease agreements. We also maintain an allowance for receivables arising from the straight-lining of rents. These receivables arise from earnings recognized in excess of amounts currently due under the lease agreements. Management exercises judgment in establishing these allowances and considers payment history and current credit status in developing these estimates. As of December 31, 2016 and 2015, we had $10,920,000 and $11,908,000, respectively, in allowances for doubtful accounts. In addition, as of December 31, 2016 and 2015, we had $2,227,000 and $2,751,000, respectively, in allowances for receivables arising from the straight-lining of rents.
Deferred Charges	Deferred Charges: Direct financing costs are deferred and amortized over the terms of the related agreements as a component of interest expense. Direct costs related to successful leasing activities are capitalized and amortized on a straight line basis over the lives of the related leases. All other deferred charges are amortized on a straight line basis, which approximates the effective interest rate method, in accordance with the terms of the agreements to which they relate.
Revenue Recognition	Revenue Recognition: We have the following revenue sources and revenue recognition policies: • Base Rent — income arising from tenant leases. These rents are recognized over the non-cancelable term of the related leases on a straight-line basis which includes the effects of rent steps and rent abatements under the leases. We commence rental revenue recognition when the tenant takes possession of the leased space and the leased space is substantially ready for its intended use. In addition, in circumstances where we provide a tenant improvement allowance for improvements that are owned by the tenant, we recognize the allowance as a reduction of rental revenue on a straight-line basis over the term of the lease. • Percentage Rent — income arising from retail tenant leases that is contingent upon tenant sales exceeding defined thresholds. These rents are recognized only after the contingency has been removed (i.e., when tenant sales thresholds have been achieved). • Hotel Revenue — income arising from the operation of the Hotel Pennsylvania which consists of rooms revenue, food and beverage revenue, and banquet revenue. Income is recognized when rooms are occupied. Food and beverage and banquet revenue is recognized when the services have been rendered. • Trade Shows Revenue — income arising from the operation of trade shows, including rentals of booths. This revenue is recognized when the trade shows have occurred. • Expense Reimbursements — revenue arising from tenant leases which provide for the recovery of all or a portion of the operating expenses and real estate taxes of the respective property. This revenue is recognized in the same periods as the expenses are incurred. • Management, Leasing and Other Fees — income arising from contractual agreements with third parties or with partially owned entities. This revenue is recognized as the related services are performed under the respective agreements.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities: ASC 815, Derivatives and Hedging, as amended, establishes accounting and reporting standards for derivative instruments, including certain derivative instruments embedded in other contracts, and for hedging activities. As of December 31, 2016 and 2015, our derivative instruments consisted of two and one interest rate swaps, respectively. We record all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the resulting designation. Derivatives used to hedge the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives used to hedge the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. For derivatives designated as fair value hedges, changes in the fair value of the derivative and the hedged item related to the hedged risk are recognized in earnings. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in other comprehensive income (loss) (outside of earnings) and subsequently reclassified to earnings when the hedged transaction affects earnings, and the ineffective portion of changes in the fair value of the derivative is recognized directly in earnings. We assess the effectiveness of each hedging relationship by comparing the changes in fair value or cash flows of the derivative hedging instrument with the changes in fair value or cash flows of the designated hedged item or transaction. For derivatives not designated as hedges, changes in fair value are recognized in earnings.
Income Taxes	Income Taxes: Vornado operates in a manner intended to enable it to continue to qualify as a REIT under Sections 856-860 of the Internal Revenue Code of 1986, as amended. Under those sections, a REIT which distributes at least 90% of its REIT taxable income as a dividend to its shareholders each year and which meets certain other conditions will not be taxed on that portion of its taxable income which is distributed to its shareholders. Vornado distributes to its shareholders 100% of its taxable income and therefore, no provision for Federal income taxes is required. Dividends distributed for the year ended December 31, 2016, were characterized, for federal income tax purposes, as 83.5% ordinary income and 16.5% long-term capital gain. Dividends distributed for the year ended December 31, 2015, were characterized, for federal income tax purposes, as long-term capital gain income. Dividends distributed for the year ended December 31, 2014, were characterized, for federal income tax purposes, as ordinary income. The Operating Partnership’s partners are required to report their respective share of taxable income on their individual tax returns. We have elected to treat certain consolidated subsidiaries, and may in the future elect to treat newly formed subsidiaries, as taxable REIT subsidiaries pursuant to an amendment to the Internal Revenue Code that became effective January 1, 2001. Taxable REIT subsidiaries may participate in non-real estate related activities and/or perform non-customary services for tenants and are subject to Federal and State income tax at regular corporate tax rates. Our taxable REIT subsidiaries had a combined current income tax expense of approximately $7,946,000, $8,322,000 and $10,777,000 for the years ended December 31, 2016, 2015 and 2014, respectively, and have immaterial differences between the financial reporting and tax basis of assets and liabilities. At December 31, 2016 and 2015, our taxable REIT subsidiaries had deferred tax assets related to net operating loss carryforwards of $98,013,000 and $97,104,000, respectively, which are included in “other assets” on our consolidated balance sheets. Prior to the quarter ended June 30, 2015, there was a full valuation allowance against these deferred tax assets because we had not determined that it is more-likely-than-not that we would use the net operating loss carryforwards to offset future taxable income. In our quarter ended June 30, 2015, based upon residential condominium unit sales, among other factors, we concluded that it was more-likely-than-not that we will generate sufficient taxable income to realize these deferred tax assets. Accordingly, we reversed $90,030,000 of the allowance for deferred tax assets and recognized an income tax benefit in our consolidated statements of income.
Marketable Securities	Our portfolio of marketable securities is comprised of equity securities that are classified as available-for-sale. Available-for-sale securities are presented on our consolidated balance sheets at fair value. Unrealized gains and losses resulting from the mark-to-market of these securities are included in “other comprehensive income (loss).” Realized gains and losses are recognized in earnings only upon the sale of the securities and are recorded based on the weighted average cost of such securities. We evaluate our portfolio of marketable securities for impairment each reporting period. For each of the securities in our portfolio with unrealized losses, we review the underlying cause of the decline in value and the estimated recovery period, as well as the severity and duration of the decline. In our evaluation, we consider our ability and intent to hold these investments for a reasonable period of time sufficient for us to recover our cost basis. We also evaluate the near-term prospects for each of these investments in relation to the severity and duration of the decline.
Redeemable Noncontrolling Interests Policy	Redeemable noncontrolling interests on Vornado’s consolidated balance sheets and redeemable partnership units on the consolidated balance sheets of the Operating Partnership are primarily comprised of Class A Operating Partnership units held by third parties and are recorded at the greater of their carrying amount or redemption value at the end of each reporting period. Changes in the value from period to period are charged to “additional capital” in Vornado’s consolidated statements of changes in equity and to “partners’ capital” on the consolidated balance sheets of the Operating Partnership. Class A units may be tendered for redemption to the Operating Partnership for cash; Vornado, at its option, may assume that obligation and pay the holder either cash or Vornado common shares on a one-for-one basis. Because the number of Vornado common shares outstanding at all times equals the number of Class A units owned by Vornado, the redemption value of each Class A unit is equivalent to the market value of one Vornado common share, and the quarterly distribution to a Class A unitholder is equal to the quarterly dividend paid to a Vornado common shareholder. Redeemable noncontrolling interests/redeemable partnership units exclude our Series G-1 through G-4 convertible preferred units and Series D-13 cumulative redeemable preferred units, as they are accounted for as liabilities in accordance with ASC 480, Distinguishing Liabilities and Equity, because of their possible settlement by issuing a variable number of Vornado common shares.