Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements, have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and with the rules and regulations of the Securities and Exchange Commission (the "SEC"), represent our assets and liabilities and operating results. The consolidated financial statements include our accounts and our partially owned and wholly owned subsidiaries as well as our Operating Partnership and its subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. 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. The primary beneficiary of a VIE is the entity that has (i) the power to direct the activities that most significantly impact the entity's economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. The primary beneficiary is required to consolidate the VIE. Empire State Realty Trust, Inc. has a variable interest in our Operating Partnership, Empire State Realty OP, L.P. and we are deemed to be the primary beneficiary. We also determined that the Operating Partnership has a variable interest in and is the primary beneficiary of ESRT 298 Mulberry, L.L.C. which is the entity through which we acquired a multifamily asset located at 298 Mulberry Street in Manhattan in December 2022 (see Note 3 Acquisitions and Dispositions). We will assess the accounting treatment for each investment we may have in the future. This assessment will include a review of each entity’s organizational agreement to determine which party has what rights and whether those rights are protective or participating. For all VIEs, we will review such agreements in order to determine which party has the power to direct the activities that most significantly impact the entity’s economic performance and benefit. In situations where we or our partner could approve, among other things, the annual budget, or leases that cover more than a nominal amount of space relative to the total rentable space at each property, we would not consolidate the investment as we consider these to be substantive participation rights that result in shared power of the activities that would most significantly impact the performance and benefit of such joint venture investment. A non-controlling interest in a consolidated subsidiary is defined as the portion of the equity (net assets) in a subsidiary not attributable, directly or indirectly, to a parent. Non-controlling interests are required to be presented as a separate component of equity in the consolidated balance sheets and in the consolidated statements of income by requiring earnings and other comprehensive income to be attributed to controlling and non-controlling interests. Accounting Estimates The preparation of the consolidated financial statements in accordance with GAAP requires management to use estimates and assumptions that in certain circumstances affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported revenues and expenses. Significant items subject to such estimates and assumptions include allocation of the purchase price of acquired real estate properties among tangible and intangible assets, determination of the useful life of real estate properties and other long-lived assets, valuation and impairment analysis of commercial real estate properties, goodwill, right-of-use assets and other long-lived assets, estimate of tenant expense reimbursements, valuation of the allowance for doubtful accounts, and valuation of derivative instruments, ground lease liabilities, senior unsecured notes, mortgage notes payable, unsecured revolving credit and term loan facilities, and equity based compensation. These estimates are prepared using management’s best judgment, after considering past, current, and expected events and economic conditions. Actual results could differ from those estimates. Revenue Recognition Rental Revenue Rental revenue includes base rents that each tenant pays in accordance with the terms of its respective lease and is reported on a straight-line basis over the non-cancellable term of the lease which includes the effects of rent steps and rent abatements under the leases. In general, we commence rental revenue recognition when the tenant takes possession of the leased space or controls the physical use of the leased space and the leased space is substantially ready for its intended use. We account for all of our leases as operating leases. Deferred rent receivables, including free rental periods and leasing arrangements allowing for increased base rent payments, are accounted for in a manner that provides an even amount of fixed lease revenues over the respective non-cancellable lease terms. Differences between rental income recognized and amounts due under the respective lease agreements are recognized as an increase or decrease to deferred rent receivables. In addition to base rent, our tenants also generally will pay their pro rata share of increases in real estate taxes and operating expenses for the building over a base year. In some leases, in lieu of paying additional rent based upon increases in building operating expenses, the tenant will pay additional rent based upon increases in an index such as the Consumer Price Index over the index value in effect during a base year, or contain fixed percentage increases over the base rent to cover escalations. We recognize rental revenue of acquired in-place above- and below-market leases at their fair values over the terms of the respective leases, including, for below-market leases, fixed option renewal periods, if any. Lease termination fees are recognized when the fees are determinable, tenant vacancy has occurred, collectability is reasonably assured, we have no continuing obligation to provide services to such former tenants and the payment is not subject to any conditions that must be met or waived. Observatory Revenue Revenues from the sale of observatory tickets are recognized upon admission or ticket expirations. Deferred revenue related to unused and unexpired tickets as of December 31, 2022 and 2021 was $1.4 million and $0.9 million, respectively, and is included in deferred revenue and other liabilities on the consolidated balance sheets. Gains on Sale/Disposition of Real Estate We record a gain on sale of real estate pursuant to provisions under Accounting Standards Codification (ASC) 610-20, Gains and Losses from the Derecognition of Nonfinancial Assets. Under ASC 610-20, we must first determine whether the transaction is a sale to a customer or non-customer. We do not sell real estate within the ordinary course of our business and therefore, expect that sale transactions will not be contracts with customers. We will next determine whether we would have a controlling financial interest in the property after the sale. If we determine that we do not have a controlling financial interest in the real estate, we would evaluate whether a contract exists under ASC 606 Revenue from Contracts with Customers and whether the buyer has obtained control of the asset that was sold. We recognize the full gain on sale of real estate when the derecognition criteria under ASC 610-20 have been met. Third-Party Management and Other Fees We earn revenue arising from contractual agreements with related party entities for asset and property management services. This revenue is recognized as the related services are performed under the respective agreements in place. Other Revenues and Fees Other revenues and fees includes parking income, legal, tax and insurance settlements, demand response energy use earnings and sales from our restaurant at the Empire State Building. Advertising and Marketing Costs Advertising and marketing costs are expensed as incurred. The expense for the years ended December 31, 2022, 2021, and 2020 was $10.8 million, $7.9 million and $7.4 million, respectively, and is included within operating expenses in our consolidated statements of operations. Real Estate Properties and Related Intangible Assets Land and buildings and improvements are recorded at cost less accumulated depreciation and amortization. The recorded cost includes cost of acquisitions, development and construction and tenant allowances and improvements. Expenditures for ordinary repairs and maintenance are charged to property operating expense as incurred. Significant replacements and betterments which improve or extend the life of the asset are capitalized. Tenant improvements which improve or extend the life of the asset are capitalized. If a tenant vacates its space prior to the contractual termination of its lease, the unamortized balance of any tenant improvements are written off if they are replaced or have no future value. For developed properties, direct and indirect costs that clearly relate to projects under development are capitalized. Costs include construction costs, professional services such as architectural and legal costs, capitalized interest and direct payroll costs. We begin capitalization when the project is probable. The assets relating to the project are stated at cost and are not depreciated. Once construction is completed and the assets are placed in service, the assets are reclassified to the appropriate asset class and depreciated in accordance with the useful lives as indicated below. Capitalization of interest ceases when the asset is ready for its intended use, which is generally near the date that a certificate of occupancy is obtained. There was no capitalized interest for the years ended December 31, 2022 and 2021. Depreciation and amortization are computed using the straight-line method for financial reporting purposes. Buildings and improvements are depreciated over the shorter of 39 years, the useful life, or the remaining term of any leasehold interest. Tenant improvement costs, which are included in building and improvements in the consolidated balance sheets, are depreciated over the shorter of (i) the related remaining lease term or (ii) the life of the improvement. Corporate and other equipment is depreciated over three to seven years. Acquisitions of properties are accounted for utilizing the acquisition method and accordingly the purchase cost is allocated to tangible and intangible assets and liabilities based on their fair values. The fair value of tangible assets acquired is determined by valuing the property as if it were vacant, applying methods similar to those used by independent appraisers of income-producing property. The resulting value is then allocated to land, buildings and improvements, and tenant improvements based on our determination of the fair value of these assets. The assumptions used in the allocation of fair values to assets acquired are based on our best estimates at the time of evaluation. Fair value is assigned to above-market and below-market leases based on the difference between (a) the contractual amounts to be paid by the tenant based on the existing lease and (b) our estimate of current market lease rates for the corresponding in-place leases, over the remaining terms of the in-place leases. Capitalized above-market lease amounts are amortized as a decrease to rental revenue over the remaining terms of the respective leases. Capitalized below-market lease amounts are amortized as an increase to rental revenue over the remaining terms of the respective leases. If a tenant vacates its space prior to the contractual termination of the lease and no rental payments are being made on the lease, any unamortized balance of the related intangible will be written off. The aggregate value of other acquired intangible assets consists of acquired ground leases and acquired in-place leases and tenant relationships. The fair value allocated to acquired in-place leases consists of a variety of components including, but not necessarily limited to: (a) the value associated with avoiding the cost of originating the acquired in-place leases (i.e. the market cost to execute a lease, including leasing commissions, if any); (b) the value associated with lost revenue related to tenant reimbursable operating costs estimated to be incurred during the assumed lease-up period (i.e. real estate taxes, insurance and other operating expenses); (c) the value associated with lost rental revenue from existing leases during the assumed lease-up period; and (d) the value associated with any other inducements to secure a tenant lease. We assess the potential for impairment of our long-lived assets, including real estate properties, annually or whenever events occur or a change in circumstances indicate that the recorded value might not be fully recoverable. We determine whether impairment in value has occurred by comparing the estimated future undiscounted cash flows expected from the use and eventual disposition of the asset to its carrying value. If the undiscounted cash flows do not exceed the carrying value, the real estate is adjusted to fair value and an impairment loss is recognized. Assets held for sale are recorded at the lower of cost or fair value less costs to sell and depreciation expense is no longer recorded. During the fourth quarter 2021, we suspended debt service related to a $30 million mortgage secured by our property in Norwalk, Connecticut and we identified this action as an indicator of impairment. We concluded that the cost basis of the asset exceeded its fair value when considering our reduced holding period given our intent to transfer property ownership to the lender. As such, we incurred a $7.7 million impairment charge in the year ended December 31, 2021. Our methodology to calculate the fair value of the property involved a combination of the discounted cash flow method, utilizing Level 3 unobservable inputs such as market capitalization rates obtained from external sources, and the market-based approach utilizing recent sales comparables. During April 2022, we transferred 383 Main Avenue, Norwalk CT back to the lender in a consensual foreclosure. Refer to Note 3 Acquisitions and Dispositions. We do not believe that the value of any of our other properties and intangible assets were impaired during the years ended December 31, 2022, 2021 and 2020. Cash and Cash Equivalents Cash and cash equivalents consist of cash on hand, government money markets, demand deposits with financial institutions and short-term liquid investments with original maturities of three months or less when purchased. Cash and cash equivalents held at major commercial banks may at times exceed the Federal Deposit Insurance Corporation limit. To date, we have not experienced any losses on our invested cash. Restricted Cash Restricted cash consists of amounts held for tenants in accordance with lease agreements such as security deposits and amounts held by lenders and/or escrow agents to provide for future real estate tax expenditures and insurance expenditures, tenant vacancy related costs and debt service obligations. Short-term Investments Short-term investments include time deposits with original maturities of greater than three months and remaining maturities of less than one year. Tenant and Other Receivables Tenant and other receivables, other than deferred rent receivable, are generally expected to be collected within one year. Deferred Leasing Costs Deferred leasing costs consist of fees incurred to initiate and renew leases, are amortized on a straight-line basis over the related lease term and the expense is included in depreciation and amortization in our consolidated statements of income. Upon the early termination of a lease, unamortized deferred leasing costs are charged to expense. Deferred Financing Costs Fees and costs incurred to obtain long-term financing have been deferred and are amortized as a component of interest expense in our consolidated statements of income over the life of the respective long-term financing on the straight-line method which approximates the effective interest method. Unamortized deferred financing costs are expensed when the associated debt is refinanced or repaid before maturity. Costs incurred in seeking debt, which do not close, are expensed in the period in which it is determined that the financing will not close. Equity Method Investments We account for investments under the equity method of accounting where we do not have control but have the ability to exercise significant influence. Under this method, investments are recorded at cost, and the investment accounts are adjusted for our share of the entities’ income or loss and for distributions and contributions. Equity income (loss) is allocated based on the portion of the ownership interest that is controlled by us. The agreements may designate different percentage allocations among investors for profits and losses; however, our recognition of the entity’s income or loss generally follows the entity’s distribution priorities, which may change upon the achievement of certain investment return thresholds. To the extent that we contributed assets to an entity, our investment in the entity is recorded at cost basis in the assets that were contributed to the entity. Upon contributing assets to an entity, we make a judgment as to whether the economic substance of the transaction is a sale. In accordance with the provisions of ASC 610-20, we will recognize a full gain on both the retained and sold portions of real estate contributed or sold to an entity by recognizing our new equity method investment interest at fair value. To the extent that the carrying amount of these investments on our combined balance sheets is different than the basis reflected at the entity level, the basis difference would be amortized over the life of the related asset and included in our share of equity in net income of the entity. On a periodic basis, we assess whether there are any indicators that the carrying value of our investments in entities may be impaired on an other than temporary basis. An investment is impaired only if management’s estimate of the fair value of the investment is less than the carrying value of the investment on an other than temporary basis. To the extent impairment has occurred, the loss shall be measured as the excess of the carrying value of the investment over the fair value of the investment. As of December 31, 2022 and 2021, we had no equity method investments. Goodwill Goodwill is tested annually for impairment and is tested for impairment more frequently if events and circumstances indicate that the asset might be impaired. An impairment loss is recognized to the extent that the carrying amount, including goodwill, exceeds the reporting unit’s fair value and the implied fair value of goodwill is less than the carrying amount of that goodwill. Non-amortizing intangible assets, such as trade names and trademarks, are subject to an annual impairment test based on fair value and amortizing intangible assets are tested whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Fair Value Fair value is a market-based measurement, not an entity-specific measurement, and should be determined based on the assumptions that market participants would use in pricing the asset or liability. As a basis for considering market participant assumptions in fair value measurements, the FASB guidance establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within levels one and two of the hierarchy) and the reporting entity's own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy). The methodologies used for valuing financial instruments have been categorized into three broad levels as follows: Level 1 - Quoted prices in active markets for identical instruments. Level 2 - Valuations based principally on other observable market parameters, including: •Quoted prices in active markets for similar instruments; •Quoted prices in less active or inactive markets for identical or similar instruments; •Other observable inputs (such as risk free interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates); and •Market corroborated inputs (derived principally from or corroborated by observable market data). Level 3 - Valuations based significantly on unobservable inputs, including: •Valuations based on third-party indications (broker quotes or counterparty quotes) which were, in turn, based significantly on unobservable inputs or were otherwise not supportable; and •Valuations based on internal models with significant unobservable inputs. These levels form a hierarchy. We follow this hierarchy for our financial instruments measured or disclosed at fair value on a recurring and nonrecurring basis and other required fair value disclosures. The classifications are based on the lowest level of input that is significant to the fair value measurement. We use the following methods and assumptions in estimating fair value disclosures for financial instruments. Cash and cash equivalents, restricted cash, short term investments, tenant and other receivables, prepaid expenses and other assets, deferred revenue, tenant security deposits, accounts payable and accrued expenses carrying values approximate their fair values due to the short term maturity of these instruments. The fair value of derivative instruments is determined using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. Although the majority of the inputs used to value our derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with our derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by ourselves and our counterparties. The impact of such credit valuation adjustments, determined based on the fair value of each individual contract, was not significant to the overall valuation. As a result, all of our derivatives were classified as Level 2 of the fair value hierarchy. The fair value of our mortgage notes payable, senior unsecured notes - Series A, B, C, D, E, F, G and H, and unsecured term loan facilities which are determined using Level 3 inputs, are estimated by discounting the future cash flows using current interest rates at which similar borrowings could be made to us. Derivative Instruments We are exposed to the effect of interest rate changes and manage these risks by following policies and procedures including the use of derivatives. To manage exposure to interest rates, derivatives are used primarily to fix the rate on debt based on floating-rate indices. We record all derivatives on the balance sheet at fair value. We incorporate credit valuation adjustments to appropriately reflect both our own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. We measure the credit risk of our derivative instruments that are subject to master netting agreements on a net basis by counterparty portfolio. For derivatives that qualify as cash flow hedges, we report the gain or loss on the derivative designated as a hedge as part of other comprehensive income (loss) and subsequently reclassify the gain or loss into income in the period that the hedged transaction affects income. Income Taxes We elected to be subject to tax as a REIT under sections 856 through 860 of the Internal Revenue Code of 1986, as amended, (the "Code"), commencing with the taxable year ended December 31, 2013 and believe that our intended manner of operations will enable us to continue to meet the requirements for qualification and taxation as a REIT. REITs are subject to a number of organizational and operational requirements, including a requirement that 90% of ordinary “REIT taxable income” (as determined without regard to the dividends paid deduction or net capital gains) be distributed. As a REIT, we will generally not be subject to U.S. federal income tax to the extent that we meet the organizational and operational requirements and our distributions equal or exceed REIT taxable income. For all periods subsequent to the effective date of our REIT election, we have met the organizational and operational requirements and distributions have exceeded net taxable income. Accordingly, no provision has been made for federal income taxes. We have elected to treat ESRT Observatory TRS, L.L.C., our subsidiary that holds our observatory operations, and ESRT Holdings TRS, L.L.C., our subsidiary that holds our third party management, restaurant, cafeteria, health clubs and certain cleaning operations, as taxable REIT subsidiaries. Taxable REIT subsidiaries may participate in non-real estate activities and/or perform non-customary services for tenants and their operations are generally subject to regular corporate income taxes. Our taxable REIT subsidiaries accounts for its income taxes in accordance with GAAP, which includes an estimate of the amount of taxes payable or refundable for the current year and deferred tax liabilities and assets for the future tax consequences of events that have been recognized in our financial statements or tax returns. The calculation of the taxable REIT subsidiaries' tax provisions may require interpreting tax laws and regulations and could result in the use of judgments or estimates which could cause its recorded tax liability to differ from the actual amount due. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The taxable REIT subsidiaries periodically assess the realizability of deferred tax assets and the adequacy of deferred tax liabilities, including the results of local, state, or federal statutory tax audits or estimates and judgments used. We apply provisions for measuring and recognizing tax benefits associated with uncertain income tax positions. Penalties and interest, if incurred, would be recorded as a component of income tax expense. As of December 31, 2022 and 2021, we do not have a liability for uncertain tax positions. As of December 31, 2022, the tax years ended December 31, 2019 through December 31, 2022 remain open for an audit by the Internal Revenue Service, state or local authorities. Share-Based Compensation Share-based compensation for time-based equity awards is measured at the fair value of the award on the date of grant and recognized as an expense on a straight-line basis over the shorter of (i) the stated vesting period, which is generally three, four or five years, or (ii) the period from the date of grant to the date the employee becomes retirement eligible, which may occur upon grant. An employee is retirement eligible when the employee attains the (i) age of 65 for awards granted in 2020 and after and age of 60 for awards granted before 2020 and (ii) the date on which the employee has first completed ten years of continuous service with us or our affiliates. Share-based compensation for market-based equity awards and performance-based equity awards is measured at the fair value of the award on the date of grant and recognized as an expense on a straight-line basis over three or four years. Additionally, for the performance-based equity awards, we assess, at each reporting period, whether it is probable that the performance conditions will be satisfied. We recognize expense respective to the number of awards we expect to vest at the conclusion of the measurement period. Changes in estimate are accounted for in the period of change through a cumulative catch-up adjustment. Any forfeitures of share-based compensation awards are recognized as they occur. The determination of fair value of these awards is subjective and involves significant estimates and assumptions including expected volatility of our stock, expected dividend yield, expected term, and assumptions of whether these awards will achieve parity with other Operating Partnership units or achieve performance thresholds. We believe that the assumptions and estimates utilized are appropriate based on the information available to management at the time of grant. Per Share Data Basic and diluted earnings per share are computed based upon the weighted average number of shares outstanding during the respective period. Segment Reporting We have identified two reportable segments: (1) Real Estate and (2) Observatory. Our real estate segment includes all activities related to the ownership, management, operation, acquisition, repositioning and disposition of our real estate assets. Our observatory segment operates the 86th and 102nd floor observatories at the Empire State Building. These two lines of businesses are managed separately because each business requires different support infrastructures, provides different services and has dissimilar economic characteristics such as investments needed, stream of revenues and different marketing strategies. We account for intersegment sales and rent as if the sales or rent were to third parties, that is, at current market prices. Recently Issued or Adopted Accounting Standards During March 2020, the FASB issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848). ASU 2020-04 contains practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance in ASU 2020-04 is optional and may be elected over time as reference rate reform activities occur. During the first quarter 2020, we elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the presentation of derivatives consistent with past presentation. We continue to evaluate the impact of the guidance and may apply other elections as applicable as additional changes in the market occur. In December 2022, the FASB issued ASU 2022-06, Reference Rate Reform (Topic 848) Deferral of the Sunset Date of Topic 848 which defers the sunset date of ASU 2022-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform to December 31, 2024. ASU 2022-06 is effective immediately for all companies. ASU 2022-06 did not have an impact on our consolidated financial statements for the year ended December 31, 2022.

The accompanying consolidated financial statements, have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and with the rules and regulations of the Securities and Exchange Commission (the "SEC"), represent our assets and liabilities and operating results. The consolidated financial statements include our accounts and our partially owned and wholly owned subsidiaries as well as our Operating Partnership and its subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.

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. The primary beneficiary of a VIE is the entity that has (i) the power to direct the activities that most significantly impact the entity's economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. The primary beneficiary is required to consolidate the VIE.

Empire State Realty Trust, Inc. has a variable interest in our Operating Partnership, Empire State Realty OP, L.P. and we are deemed to be the primary beneficiary. We also determined that the Operating Partnership has a variable interest in and is the primary beneficiary of ESRT 298 Mulberry, L.L.C. which is the entity through which we acquired a multifamily asset located at 298 Mulberry Street in Manhattan in December 2022 (see Note 3 Acquisitions and Dispositions).

We will assess the accounting treatment for each investment we may have in the future. This assessment will include a review of each entity’s organizational agreement to determine which party has what rights and whether those rights are protective or participating. For all VIEs, we will review such agreements in order to determine which party has the power to direct the activities that most significantly impact the entity’s economic performance and benefit. In situations where we or our partner could approve, among other things, the annual budget, or leases that cover more than a nominal amount of space relative to the total rentable space at each property, we would not consolidate the investment as we consider these to be substantive participation rights that result in shared power of the activities that would most significantly impact the performance and benefit of such joint venture investment.

A non-controlling interest in a consolidated subsidiary is defined as the portion of the equity (net assets) in a subsidiary not attributable, directly or indirectly, to a parent. Non-controlling interests are required to be presented as a separate component of equity in the consolidated balance sheets and in the consolidated statements of income by requiring earnings and other comprehensive income to be attributed to controlling and non-controlling interests.

The preparation of the consolidated financial statements in accordance with GAAP requires management to use estimates and assumptions that in certain circumstances affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, and the reported revenues and expenses. Significant items subject to such estimates and assumptions include allocation of the purchase price of acquired real estate properties among tangible and intangible assets, determination of the useful life of real estate properties and other long-lived assets, valuation and impairment analysis of commercial real estate properties, goodwill, right-of-use assets and other long-lived assets, estimate of tenant expense reimbursements, valuation of the allowance for doubtful accounts, and valuation of derivative instruments, ground lease liabilities, senior unsecured notes, mortgage notes payable, unsecured revolving credit and term loan facilities, and equity based compensation. These estimates are prepared using management’s best judgment, after considering past, current, and expected events and economic conditions. Actual results could differ from those estimates.

Rental revenue includes base rents that each tenant pays in accordance with the terms of its respective lease and is reported on a straight-line basis over the non-cancellable term of the lease which includes the effects of rent steps and rent abatements under the leases. In general, we commence rental revenue recognition when the tenant takes possession of the leased space or controls the physical use of the leased space and the leased space is substantially ready for its intended use. We account for all of our leases as operating leases. Deferred rent receivables, including free rental periods and leasing arrangements allowing for increased base rent payments, are accounted for in a manner that provides an even amount of fixed lease revenues over the respective non-cancellable lease terms. Differences between rental income recognized and amounts due under the respective lease agreements are recognized as an increase or decrease to deferred rent receivables.

In addition to base rent, our tenants also generally will pay their pro rata share of increases in real estate taxes and operating expenses for the building over a base year. In some leases, in lieu of paying additional rent based upon increases in building operating expenses, the tenant will pay additional rent based upon increases in an index such as the Consumer Price Index over the index value in effect during a base year, or contain fixed percentage increases over the base rent to cover escalations.

Revenues from the sale of observatory tickets are recognized upon admission or ticket expirations. Deferred revenue related to unused and unexpired tickets as of December 31, 2022 and 2021 was $1.4 million and $0.9 million, respectively, and is included in deferred revenue and other liabilities on the consolidated balance sheets.

We record a gain on sale of real estate pursuant to provisions under Accounting Standards Codification (ASC) 610-20, Gains and Losses from the Derecognition of Nonfinancial Assets. Under ASC 610-20, we must first determine whether the transaction is a sale to a customer or non-customer. We do not sell real estate within the ordinary course of our business and therefore, expect that sale transactions will not be contracts with customers. We will next determine whether we would have a controlling financial interest in the property after the sale. If we determine that we do not have a controlling financial interest in the real estate, we would evaluate whether a contract exists under ASC 606 Revenue from Contracts with Customers and whether the buyer has obtained control of the asset that was sold. We recognize the full gain on sale of real estate when the derecognition criteria under ASC 610-20 have been met.

Land and buildings and improvements are recorded at cost less accumulated depreciation and amortization. The recorded cost includes cost of acquisitions, development and construction and tenant allowances and improvements. Expenditures for ordinary repairs and maintenance are charged to property operating expense as incurred. Significant replacements and betterments which improve or extend the life of the asset are capitalized. Tenant improvements which improve or extend the life of the asset are capitalized. If a tenant vacates its space prior to the contractual termination of its lease, the unamortized balance of any tenant improvements are written off if they are replaced or have no future value. For developed properties, direct and indirect costs that clearly relate to projects under development are capitalized. Costs include construction costs, professional services such as architectural and legal costs, capitalized interest and direct payroll costs. We begin capitalization when the project is probable. The assets relating to the project are stated at cost and are not depreciated. Once construction is completed and the assets are placed in service, the assets are reclassified to the appropriate asset class and depreciated in accordance with the useful lives as indicated below. Capitalization of interest ceases when the asset is ready for its intended use, which is generally near the date that a certificate of occupancy is obtained. There was no capitalized interest for the years ended December 31, 2022 and 2021.

Depreciation and amortization are computed using the straight-line method for financial reporting purposes. Buildings and improvements are depreciated over the shorter of 39 years, the useful life, or the remaining term of any leasehold interest. Tenant improvement costs, which are included in building and improvements in the consolidated balance sheets, are depreciated over the shorter of (i) the related remaining lease term or (ii) the life of the improvement. Corporate and other equipment is depreciated over three to seven years.

Acquisitions of properties are accounted for utilizing the acquisition method and accordingly the purchase cost is allocated to tangible and intangible assets and liabilities based on their fair values. The fair value of tangible assets acquired is determined by valuing the property as if it were vacant, applying methods similar to those used by independent appraisers of income-producing property. The resulting value is then allocated to land, buildings and improvements, and tenant improvements based on our determination of the fair value of these assets. The assumptions used in the allocation of fair values to assets acquired are based on our best estimates at the time of evaluation.

Fair value is assigned to above-market and below-market leases based on the difference between (a) the contractual amounts to be paid by the tenant based on the existing lease and (b) our estimate of current market lease rates for the corresponding in-place leases, over the remaining terms of the in-place leases. Capitalized above-market lease amounts are amortized as a decrease to rental revenue over the remaining terms of the respective leases. Capitalized below-market lease amounts are amortized as an increase to rental revenue over the remaining terms of the respective leases. If a tenant vacates its space prior to the contractual termination of the lease and no rental payments are being made on the lease, any unamortized balance of the related intangible will be written off.

The aggregate value of other acquired intangible assets consists of acquired ground leases and acquired in-place leases and tenant relationships. The fair value allocated to acquired in-place leases consists of a variety of components including, but not necessarily limited to: (a) the value associated with avoiding the cost of originating the acquired in-place leases (i.e. the market cost to execute a lease, including leasing commissions, if any); (b) the value associated with lost revenue related to tenant reimbursable operating costs estimated to be incurred during the assumed lease-up period (i.e. real estate taxes, insurance and other operating expenses); (c) the value associated with lost rental revenue from existing leases during the assumed lease-up period; and (d) the value associated with any other inducements to secure a tenant lease.

We assess the potential for impairment of our long-lived assets, including real estate properties, annually or whenever events occur or a change in circumstances indicate that the recorded value might not be fully recoverable. We determine whether impairment in value has occurred by comparing the estimated future undiscounted cash flows expected from the use and eventual disposition of the asset to its carrying value. If the undiscounted cash flows do not exceed the carrying value, the real estate is adjusted to fair value and an impairment loss is recognized. Assets held for sale are recorded at the lower of cost or fair value less costs to sell and depreciation expense is no longer recorded.

During the fourth quarter 2021, we suspended debt service related to a $30 million mortgage secured by our property in Norwalk, Connecticut and we identified this action as an indicator of impairment. We concluded that the cost basis of the asset exceeded its fair value when considering our reduced holding period given our intent to transfer property ownership to the lender. As such, we incurred a $7.7 million impairment charge in the year ended December 31, 2021. Our methodology to calculate the fair value of the property involved a combination of the discounted cash flow method, utilizing Level 3 unobservable inputs such as market capitalization rates obtained from external sources, and the market-based approach utilizing recent sales comparables. During April 2022, we transferred 383 Main Avenue, Norwalk CT back to the lender in a consensual foreclosure. Refer to Note 3 Acquisitions and Dispositions. We do not believe that the value of any of our other properties and intangible assets were impaired during the years ended December 31, 2022, 2021 and 2020.

Cash and cash equivalents consist of cash on hand, government money markets, demand deposits with financial institutions and short-term liquid investments with original maturities of three months or less when purchased. Cash and cash equivalents held at major commercial banks may at times exceed the Federal Deposit Insurance Corporation limit. To date, we have not experienced any losses on our invested cash.

Deferred leasing costs consist of fees incurred to initiate and renew leases, are amortized on a straight-line basis over the related lease term and the expense is included in depreciation and amortization in our consolidated statements of income. Upon the early termination of a lease, unamortized deferred leasing costs are charged to expense.

Fees and costs incurred to obtain long-term financing have been deferred and are amortized as a component of interest expense in our consolidated statements of income over the life of the respective long-term financing on the straight-line method which approximates the effective interest method. Unamortized deferred financing costs are expensed when the associated debt is refinanced or repaid before maturity. Costs incurred in seeking debt, which do not close, are expensed in the period in which it is determined that the financing will not close.

We account for investments under the equity method of accounting where we do not have control but have the ability to exercise significant influence. Under this method, investments are recorded at cost, and the investment accounts are adjusted for our share of the entities’ income or loss and for distributions and contributions. Equity income (loss) is allocated based on the portion of the ownership interest that is controlled by us. The agreements may designate different percentage allocations among investors for profits and losses; however, our recognition of the entity’s income or loss generally follows the entity’s distribution priorities, which may change upon the achievement of certain investment return thresholds.

To the extent that we contributed assets to an entity, our investment in the entity is recorded at cost basis in the assets that were contributed to the entity. Upon contributing assets to an entity, we make a judgment as to whether the economic substance of the transaction is a sale. In accordance with the provisions of ASC 610-20, we will recognize a full gain on both the retained and sold portions of real estate contributed or sold to an entity by recognizing our new equity method investment interest at fair value.

On a periodic basis, we assess whether there are any indicators that the carrying value of our investments in entities may be impaired on an other than temporary basis. An investment is impaired only if management’s estimate of the fair value of the investment is less than the carrying value of the investment on an other than temporary basis. To the extent impairment has occurred, the loss shall be measured as the excess of the carrying value of the investment over the fair value of the investment.

Goodwill is tested annually for impairment and is tested for impairment more frequently if events and circumstances indicate that the asset might be impaired. An impairment loss is recognized to the extent that the carrying amount, including goodwill, exceeds the reporting unit’s fair value and the implied fair value of goodwill is less than the carrying amount of that goodwill. Non-amortizing intangible assets, such as trade names and trademarks, are subject to an annual impairment test based on fair value and amortizing intangible assets are tested whenever events or changes in circumstances indicate that the carrying amount may not be recoverable.

assumptions in fair value measurements, the FASB guidance establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within levels one and two of the hierarchy) and the reporting entity's own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy).

These levels form a hierarchy. We follow this hierarchy for our financial instruments measured or disclosed at fair value on a recurring and nonrecurring basis and other required fair value disclosures. The classifications are based on the lowest level of input that is significant to the fair value measurement.

Cash and cash equivalents, restricted cash, short term investments, tenant and other receivables, prepaid expenses and other assets, deferred revenue, tenant security deposits, accounts payable and accrued expenses carrying values approximate their fair values due to the short term maturity of these instruments.

The fair value of derivative instruments is determined using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. Although the majority of the inputs used to value our derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with our derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by ourselves and our counterparties. The impact of such credit valuation adjustments, determined based on the fair value of each individual contract, was not significant to the overall valuation. As a result, all of our derivatives were classified as Level 2 of the fair value hierarchy.

The fair value of our mortgage notes payable, senior unsecured notes - Series A, B, C, D, E, F, G and H, and unsecured term loan facilities which are determined using Level 3 inputs, are estimated by discounting the future cash flows using current interest rates at which similar borrowings could be made to us.

We are exposed to the effect of interest rate changes and manage these risks by following policies and procedures including the use of derivatives. To manage exposure to interest rates, derivatives are used primarily to fix the rate on debt based on floating-rate indices. We record all derivatives on the balance sheet at fair value. We incorporate credit valuation adjustments to appropriately reflect both our own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. We measure the credit risk of our derivative instruments that are subject to master netting agreements on a net basis by counterparty portfolio. For derivatives that qualify as cash flow hedges, we report the gain or loss on the derivative designated as a hedge as part of other comprehensive income (loss) and subsequently reclassify the gain or loss into income in the period that the hedged transaction affects income.

We elected to be subject to tax as a REIT under sections 856 through 860 of the Internal Revenue Code of 1986, as amended, (the "Code"), commencing with the taxable year ended December 31, 2013 and believe that our intended manner of operations will enable us to continue to meet the requirements for qualification and taxation as a REIT. REITs are subject to a number of organizational and operational requirements, including a requirement that 90% of ordinary “REIT taxable income” (as determined without regard to the dividends paid deduction or net capital gains) be distributed. As a REIT, we will generally not be subject to U.S. federal income tax to the extent that we meet the organizational and operational requirements and our distributions equal or exceed REIT taxable income. For all periods subsequent to the effective date of our REIT election, we have met the organizational and operational requirements and distributions have exceeded net taxable income. Accordingly, no provision has been made for federal income taxes.

We have elected to treat ESRT Observatory TRS, L.L.C., our subsidiary that holds our observatory operations, and ESRT Holdings TRS, L.L.C., our subsidiary that holds our third party management, restaurant, cafeteria, health clubs and certain cleaning operations, as taxable REIT subsidiaries. Taxable REIT subsidiaries may participate in non-real estate activities and/or perform non-customary services for tenants and their operations are generally subject to regular corporate income taxes. Our taxable REIT subsidiaries accounts for its income taxes in accordance with GAAP, which includes an estimate of the amount of taxes payable or refundable for the current year and deferred tax liabilities and assets for the future tax consequences of events that have been recognized in our financial statements or tax returns. The calculation of the taxable REIT subsidiaries' tax provisions may require interpreting tax laws and regulations and could result in the use of judgments or estimates which could cause its recorded tax liability to differ from the actual amount due. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The taxable REIT subsidiaries periodically assess the realizability of deferred tax assets and the adequacy of deferred tax liabilities, including the results of local, state, or federal statutory tax audits or estimates and judgments used.

We apply provisions for measuring and recognizing tax benefits associated with uncertain income tax positions. Penalties and interest, if incurred, would be recorded as a component of income tax expense. As of December 31, 2022 and 2021, we do not have a liability for uncertain tax positions. As of December 31, 2022, the tax years ended December 31, 2019 through December 31, 2022 remain open for an audit by the Internal Revenue Service, state or local authorities.

Share-based compensation for time-based equity awards is measured at the fair value of the award on the date of grant and recognized as an expense on a straight-line basis over the shorter of (i) the stated vesting period, which is generally three, four or five years, or (ii) the period from the date of grant to the date the employee becomes retirement eligible, which may occur upon grant. An employee is retirement eligible when the employee attains the (i) age of 65 for awards granted in 2020 and after and age of 60 for awards granted before 2020 and (ii) the date on which the employee has first completed ten years of continuous service with us or our affiliates. Share-based compensation for market-based equity awards and performance-based equity awards is measured at the fair value of the award on the date of grant and recognized as an expense on a straight-line basis over three or four years. Additionally, for the performance-based equity awards, we assess, at each reporting period, whether it is probable that the performance conditions will be satisfied. We recognize expense respective to the number of awards we expect to vest at the conclusion of the measurement period. Changes in estimate are accounted for in the period of change through a cumulative catch-up adjustment. Any forfeitures of share-based compensation awards are recognized as they occur.

The determination of fair value of these awards is subjective and involves significant estimates and assumptions including expected volatility of our stock, expected dividend yield, expected term, and assumptions of whether these awards will achieve parity with other Operating Partnership units or achieve performance thresholds. We believe that the assumptions and estimates utilized are appropriate based on the information available to management at the time of grant.

We have identified two reportable segments: (1) Real Estate and (2) Observatory. Our real estate segment includes all activities related to the ownership, management, operation, acquisition, repositioning and disposition of our real estate assets. Our observatory segment operates the 86th and 102nd floor observatories at the Empire State Building. These two lines of businesses are managed separately because each business requires different support infrastructures, provides different services

During March 2020, the FASB issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848). ASU 2020-04 contains practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance in ASU 2020-04 is optional and may be elected over time as reference rate reform activities occur. During the first quarter 2020, we elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the presentation of derivatives consistent with past presentation. We continue to evaluate the impact of the guidance and may apply other elections as applicable as additional changes in the market occur.

In December 2022, the FASB issued ASU 2022-06, Reference Rate Reform (Topic 848) Deferral of the Sunset Date of Topic 848 which defers the sunset date of ASU 2022-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform to December 31, 2024. ASU 2022-06 is effective immediately for all companies. ASU 2022-06 did not have an impact on our consolidated financial statements for the year ended December 31, 2022.