Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings Except as described below, as of June 30, 2023, 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 claim 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. The Claimants had opted out of a prior class action bringing similar claims that were settled with court approval. The 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. The Respondents believe that such award in favor of the Claimants is entirely without merit and, in an action filed in the United States District Court for the Southern District of New York, sought to vacate that portion of the award. On September 27, 2021, the court denied the Respondents' motion to vacate and entered judgement in the aforementioned amount, inclusive of accumulated interest. The Respondents have appealed that ruling. On May 10, 2022, the Respondents moved to dismiss the appeal and judgment on the grounds that a recent decision of the United States Supreme Court held that the federal courts have no subject matter jurisdiction over the case. The Claimants opposed the motion. On April 20, 2023, the federal appeals court granted the motion and the federal court action challenging the award was dismissed. On April 21, 2023, the Respondents filed a petition to vacate in part and otherwise confirm in New York State court. On April 28, 2023, the Claimants filed a motion to confirm in that same court. On July 31, 2023, the New York State court denied the Respondents’ petition to vacate in part and confirmed the award. The Respondents believe that ruling is incorrect and are considering their options with respect thereto. In addition, certain of the Claimants in the federal court action sought to pursue claims in that case against the Respondents. The 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., our former general counsel, have defense and indemnity rights from us with respect to this arbitration. Unfunded Capital Expenditures At June 30, 2023, we estimate that we will incur approximately $138.4 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, additional property level mortgage financings, our unsecured credit facility, 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 June 30, 2023, we held on deposit at various major financial institutions cash and cash equivalents and restricted cash balances in excess of amounts insured by the FDIC. 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 June 30, 2023, 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 Certain of our properties have been inspected for soil contamination due to pollutants, which may have occurred prior to our ownership of these properties or subsequently in connection with its development and/or its use. Required remediation to such properties has been completed, other than our post-closing obligations for remediation at our previously owned Westport retail assets, as discussed in more detail in our Annual Report, and at our previously owned 500 Mamaroneck property as discussed in “Financial Statements - Note 3. Acquisitions and Dispositions.” As of June 30, 2023, with the exception of these three 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. We expect that resolution of the environmental matters relating to the above will not have a material impact on our business, assets, consolidated financial condition, results of operations or liquidity. 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.