Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings Except as described below, as of March 31, 2024, we were not involved in any material litigation, nor, to our knowledge, was any material litigation threatened against us or our properties, other than routine litigation arising in the ordinary course of business such as disputes with tenants. We believe that the costs and related liabilities, if any, which may result from such actions will not materially affect our condensed consolidated financial position, operating results or liquidity. As previously disclosed, in October 2014, 12 former investors (the "Claimants") in Empire State Building Associates L.L.C. (“ESBA”), which, prior to the IPO, owned the fee title to the Empire State Building, filed an arbitration with the American Arbitration Association against Peter L. Malkin, Anthony E. Malkin, Thomas N. Keltner, Jr., and our subsidiary ESRT MH Holdings LLC, the former supervisor of ESBA, (the "Respondents"). The statement of claim (also filed later in federal court in New York for the expressed purpose of tolling the statute of limitations) alleged breach of fiduciary duty and related claims in connection with the IPO and formation transactions and sought monetary damages and declaratory relief. Claimants had opted out of a prior class action bringing similar claims that were settled with court approval. Respondents filed an answer and counterclaims. In March 2015, the federal court action was stayed on consent of all parties pending the arbitration. Arbitration hearings started in May 2016 and concluded in August 2018. On August 26, 2020, the arbitration panel issued an award that denied all Claimants’ claims with one exception, on which it awarded the Claimants approximately $1.2 million, inclusive of seven years of interest through October 2, 2020. This amount was recorded as an IPO litigation expense in the consolidated statements of operations for the year ended December 31, 2020. Respondents believe that such award in favor of the Claimants is entirely without merit and sought to vacate that portion of the award. On July 31, 2023, the New York State court denied the Respondents’ petition to vacate in part and confirmed the award. On January 22, 2024, that court entered judgment in favor of the Claimants (save for one Claimant, whose petition to confirm is still pending in New York state court) in an amount of approximately $1.26 million, inclusive of interest. The Respondents believe those rulings are incorrect and have appealed them. In addition, certain of the Claimants in the federal court action brought to toll the statute of limitations and sought to pursue claims in that case against the Respondents. Respondents believe that any such claims are meritless. The magistrate judge assigned to the action has issued a Report and Recommendation rejecting the Claimants’ claims; the district judge will decide whether to adopt the Report and Recommendation. Pursuant to indemnification agreements which were made with our directors, executive officers and chairman emeritus as part of our formation transactions, Anthony E. Malkin, Peter L. Malkin and Thomas N. Keltner, Jr. have defense and indemnity rights from us with respect to this arbitration. Unfunded Capital Expenditures At March 31, 2024, we estimate that we will incur approximately $125.2 million of capital expenditures (including tenant improvements and leasing commissions) on our properties pursuant to existing lease agreements. We expect to fund these capital expenditures with operating cash flow, cash on hand and other borrowings. Future property acquisitions may require substantial capital investments for refurbishment and leasing costs. We expect that these financing requirements will be met in a similar fashion. Concentration of Credit Risk Financial instruments that subject us to credit risk consist primarily of cash and cash equivalents, restricted cash, short-term investments, tenant and other receivables and deferred rent receivables. At March 31, 2024, we held on deposit at various major financial institutions cash and cash equivalents and restricted cash balances in excess of amounts insured by the Federal Deposit Insurance Corporation. Asset Retirement Obligations We are required to accrue costs that we are legally obligated to incur on retirement of our properties which result from acquisition, construction, development and/or normal operation of such properties. Retirement includes sale, abandonment or disposal of a property. Under that standard, a conditional asset retirement obligation represents a legal obligation to perform an asset retirement activity in which the timing and/or method of settlement is conditional on a future event that may or may not be within a company’s control and a liability for a conditional asset retirement obligation must be recorded if the fair value of the obligation can be reasonably estimated. Environmental site assessments and investigations have identified asbestos or asbestos- containing building materials in certain of our properties. As of March 31, 2024, management has no plans to remove or alter these properties in a manner that would trigger federal and other applicable regulations for asbestos removal, and accordingly, the obligations to remove the asbestos or asbestos-containing building materials from these properties have indeterminable settlement dates. As such, we are unable to reasonably estimate the fair value of the associated conditional asset retirement obligation. However ongoing asbestos abatement, maintenance programs and other required documentation are carried out as required and related costs are expensed as incurred. Other Environmental Matters Under various federal, state and/or local laws, ordinances and regulations, as a current or former owner or operator of real property, we may be liable for costs and damages resulting from the presence or release of hazardous substances, waste, or petroleum products at, on, in, under or from such property, including costs for investigation or remediation, natural resource damages, or third-party liability for personal injury or property damage. These laws often impose liability without regard to whether the owner or operator knew of, or was responsible for, the presence or release of such materials, and the liability may be joint and several. Some of our properties have been or may be impacted by contamination arising from current or prior uses of the property or adjacent properties for commercial, industrial or other purposes. Such contamination may arise from spills of petroleum or hazardous substances or releases from tanks used to store such materials. We also may be liable for the costs of remediating contamination at off-site disposal or treatment facilities when we arrange for disposal or treatment of hazardous substances at such facilities, regardless of whether we comply with environmental laws in doing so. The presence of contamination or the failure to remediate contamination on our properties may adversely affect our ability to attract and/or retain tenants, and our ability to develop or sell or borrow against those properties. In addition to potential liability for cleanup costs, private plaintiffs may bring claims for personal injury, property damage or for similar reasons. Environmental laws also may create liens on contaminated sites in favor of the government for damages and costs it incurs to address such contamination. Moreover, if contamination is discovered on our properties, environmental laws may impose restrictions on the manner in which that property may be used or how businesses may be operated on that property. Some of our properties are adjacent to or near other properties which are used for industrial or commercial purposes or have contained or currently contain underground storage tanks used to store petroleum products or other hazardous or toxic substances. Releases from these properties could impact our properties. In addition, some of our properties have previously been used by former owners or tenants for commercial or industrial activities, e.g., gas stations and dry cleaners, and a portion of the Metro Tower site is currently used for automobile parking and was formerly leased to a fueling facility that may release petroleum products or other hazardous or toxic substances at such properties or to surrounding properties. While certain properties contain or contained uses that could have or have impacted our properties, we are not aware of any liabilities related to environmental contamination that we believe will have a material adverse effect on our operations. We have post-closing obligations related to the 69-97 and 103-107 Main Street, Westport, Connecticut properties that we sold in February 2023 to (i) close out a voluntary remediation program at 69-97 Main Street to address residual impacts of prior presence of underground storage tanks and (ii) comply with a consent order issued by the Connecticut Department of Environmental Protection to investigate soil conditions at 103-107 Main Street. We believe any expenses incurred to close out and comply with the remediation program and consent order, respectively, will be immaterial to the results of our operations. In addition, our properties are subject to various federal, state and local environmental and health and safety laws and regulations. Noncompliance with these laws and regulations could subject us or our tenants to liability. These liabilities could affect a tenant’s ability to make rental payments to us. Moreover, changes in laws could increase the potential costs of compliance with such laws and regulations or increase liability for noncompliance. This may result in significant unanticipated expenditures. We sometimes require our tenants to comply with environmental and health and safety laws and regulations and to indemnify us for any related liabilities in our leases with them. But in the event of the bankruptcy or inability of any of our tenants to satisfy such obligations, we may be required to satisfy such obligations. We are not presently aware of any instances of material non-compliance with environmental or health and safety laws or regulations at our properties, and we believe that we and/or our tenants have all material permits and approvals necessary under current laws and regulations to operate our properties. In addition, we may become subject to new compliance requirements and/or new costs or taxes associated with natural resource or energy usage and related emissions (such as a carbon tax), which could increase our operating costs. In particular, as the owner of large commercial buildings in New York City, we are subject to Local Law 97 passed by the New York City Council in April 2019, which for each such building establishes annual limits for greenhouse gas emissions, requires yearly emissions reports beginning in May 2025, and imposes penalties for emissions above such limits. Based upon our present understanding of the law and calculations related thereto, we expect to pay no fine on any building in our commercial portfolio in the 2024-2029 first period of enforcement. As the owner or operator of real property, we may also incur liability based on various building conditions. For example, environmental site assessments and investigations have identified asbestos or asbestos-containing material ("ACM") in certain of our properties, and it is possible that other properties that we currently own or operate or those we acquire or operate in the future contain, may contain, or may have contained ACM. Environmental and health and safety laws require that ACM be properly managed and maintained and may impose fines or penalties on owners, operators or employers for non-compliance with those requirements. These requirements include special precautions, such as removal, abatement or air monitoring, if ACM would be disturbed during maintenance, redevelopment or demolition of a building, potentially resulting in substantial costs. In addition, we may be subject to liability for personal injury or property damage sustained as a result of releases of ACM into the environment. We are not presently aware of any material liabilities related to building conditions, including any instances of material non-compliance with asbestos requirements or any material liabilities related to asbestos. Our properties may contain or develop harmful mold or suffer from other indoor air quality issues, which could lead to liability for adverse health effects or property damage or costs for remediation. When excessive moisture accumulates in buildings or on building materials, mold growth may occur, particularly if the moisture problem remains undiscovered or is not addressed over a period of time. Some molds may produce airborne toxins or irritants. Indoor air quality issues can also stem from inadequate ventilation, chemical contamination from indoor or outdoor sources, and other biological contaminants such as pollen, viruses and bacteria. Indoor exposure to airborne toxins or irritants above certain levels can be alleged to cause a variety of adverse health effects and symptoms, including allergic or other reactions. As a result, the presence of significant mold or other airborne contaminants at any of our properties could require us to undertake a costly remediation program to contain or remove the mold or other airborne contaminants from the affected property or increase indoor ventilation. In addition, the presence of significant mold or other airborne contaminants could expose us to liability from our tenants, employees of our tenants or others if property damage or personal injury occurs. We are not presently aware of any material adverse indoor air quality issues at our properties. As of March 31, 2024, with the exception of the Westport assets, management believes that there are no obligations related to environmental remediation other than maintaining the affected sites in conformity with the relevant authority’s mandates and filing the required documents. All such maintenance costs are expensed as incurred. However, we cannot be certain that we have identified all environmental liabilities at our properties, that all necessary remediation actions have been or will be undertaken at our properties or that we will be indemnified, in full or at all, in the event that such environmental liabilities arise. Insurance Coverage We carry insurance coverage on our properties of types and in amounts with deductibles that we believe are in line with coverage customarily obtained by owners of similar properties.