Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation. The consolidated financial statements include our investments in 100% owned subsidiaries and majority owned subsidiaries that are controlled by us. References to we, us, our and the Company, refer to Equity Commonwealth and its consolidated subsidiaries as of December 31, 2018, unless the context indicates otherwise. All intercompany transactions and balances have been eliminated. Real Estate Properties. We record real estate properties at cost. We depreciate real estate investments on a straight line basis over estimated useful lives of up to 40 years for buildings and improvements, and up to 12 years for personal property. Each time we enter into a new lease, or materially modify an existing lease, we evaluate its classification as either a capital or operating lease. The classification of a lease as capital or operating affects the carrying value of a property, as well as our recognition of rental payments as revenue. These evaluations require us to make estimates of, among other things, the remaining useful life and fair market value of a leased property, appropriate discount rates and future cash flows. We allocate the consideration paid for our properties among land, buildings and improvements and, for properties that qualify as acquired businesses under the Business Combinations Topic of the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC), to identified intangible assets and liabilities, consisting of the value of above market and below market leases, the value of acquired in place leases and the value of tenant relationships. Purchase price allocations and the determination of useful lives are based on our estimates and, under some circumstances, studies from independent real estate appraisal firms to provide market information and evaluations that are relevant to our purchase price allocations and determinations of useful lives; however, we are ultimately responsible for the purchase price allocations and determination of useful lives. We allocate the consideration to land, buildings and improvements based on a determination of the fair values of these assets assuming the property is vacant. We determine the fair value of a property using methods that we believe are similar to those used by independent appraisers. Purchase price allocations to above market and below market leases are based on the estimated present value (using an interest rate which reflects our assessment of the risks associated with the leases acquired) of the difference between (1) the contractual amounts to be paid pursuant to the acquired in place leases and (2) our estimate of fair market lease rates for the corresponding leases, measured over a period equal to the remaining non-cancelable terms of the respective leases. Purchase price allocations to acquired in place leases and tenant relationships are determined as the excess of (1) the purchase price paid for a property after adjusting existing in place leases to estimated market rental rates over (2) the estimated fair value of the property as if vacant. We aggregate this value between acquired in place lease values and tenant relationships based on our evaluation of the specific characteristics of each tenant's lease; however, the value of tenant relationships has not been separated from acquired in place lease value for our properties because we believe such value and related amortization expense is immaterial for acquisitions reflected in our historical financial statements. We consider certain factors in performing these analyses including estimates of carrying costs during the expected lease up periods, including real estate taxes, insurance and other operating income and expenses and costs to execute similar leases in current market conditions, such as leasing commissions, legal and other related costs. If we believe the value of tenant relationships is material in the future, those amounts will be separately allocated and amortized over the estimated lives of the relationships. We recognize the excess, if any, of the consideration paid over amounts allocated to land, buildings and improvements and identified intangible assets and liabilities as goodwill and we recognize gains if amounts allocated exceed the consideration paid. We amortize capitalized above market lease values (presented in our consolidated balance sheets as acquired real estate leases) as a reduction to rental income over the remaining terms of the respective leases. We amortize capitalized below market lease values as an increase to rental income over the remaining terms of the respective leases. We amortize the value of acquired in place leases exclusive of the value of above market and below market acquired in place leases to expense over the remaining terms of the respective leases. If a lease is terminated prior to its stated expiration, the unamortized lease intangibles relating to that lease is written off. We review our properties for impairment quarterly, or whenever events or changes in circumstances indicate that their carrying amounts may not be recoverable. Impairment indicators may include our decision to dispose of an asset before the end of its estimated useful life, declining tenant occupancy, lack of progress releasing vacant space, tenant bankruptcies, low long term prospects for improvement in property performance, weak or declining tenant profitability, and cash flow or liquidity. When indicators of potential impairment are present that suggest that the carrying amounts of real estate assets may not be recoverable, we assess the recoverability of these assets by determining whether the respective carrying values will be recovered through the estimated undiscounted future operating cash flows expected from the use of the assets and their eventual disposition. The determination of undiscounted cash flow includes consideration of many factors including income to be earned from the investment over our anticipated hold period, holding costs (exclusive of interest), estimated selling prices, and prevailing economic and market conditions. In the event that such expected undiscounted future cash flows do not exceed the carrying values, we estimate the fair value of the assets and record an impairment charge equal to the amount by which the carrying value exceeds the estimated fair value. Estimated fair values are calculated based on the following information, (i) recent third party estimates of market value, (ii) market prices for comparable properties, or (iii) the present value of future cash flows. During the years ended December 31, 2018, 2017, and 2016 we recorded a loss on asset impairment in continuing operations totaling $12.1 million, $19.7 million and $58.5 million respectively, to reduce the carrying value of properties to their estimated fair values (see Note 15). When we classify properties as held for sale, we discontinue the recording of depreciation expense and estimate their fair value less costs to sell. If we determine that the carrying value for these properties exceed their estimated fair value less costs to sell, we record a loss on asset impairment. Certain of our real estate assets contain hazardous substances, including asbestos. We believe any asbestos in our buildings is contained in accordance with current regulations. If we remove the asbestos or renovate or demolish these properties, certain environmental regulations govern the manner in which the asbestos must be handled and removed. We do not believe that there are other environmental conditions or issues at any of our properties that have had or will have a material adverse effect on us. However, no assurances can be given that conditions or issues are not present at our properties or that costs we may be required to incur in the future to remediate contamination or comply with environmental, health and safety laws will not have a material adverse effect on our business or financial condition. As of December 31, 2018 and 2017, we did not have any accrued environmental remediation costs. Cash and Cash Equivalents. Our cash and cash equivalents consist of cash maintained in time deposits, depository accounts and money market accounts. We continually monitor the credit ratings of the financial institutions holding our deposits to minimize our exposure to credit risk. Throughout the year, we have cash balances in excess of federally insured limits deposited with various financial institutions. We do not believe we are exposed to any significant credit risk on cash and cash equivalents. Marketable Securities. All of our marketable securities are classified as available-for-sale and consisted of United States Treasury notes and common stock. Available-for-sale securities are presented on our consolidated balance sheets at fair value. Changes in values of the United States Treasury notes are recognized in cumulative other comprehensive loss. Realized gains and losses are recognized in earnings only upon the sale of the United States Treasury notes. Changes in values of common stock prior to their sale in March 2018, were recognized in interest and other income, net on the consolidated statements of operations. We evaluate our marketable securities for impairment each reporting period. For securities 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. To the extent an other-than-temporary impairment is deemed to have occurred, an impairment charge is recorded and a new cost basis is established. Restricted Cash. Restricted cash consists of amounts escrowed for future real estate taxes, insurance, leasing costs, capital expenditures and debt service, as required by our mortgage debt, as well as security deposits paid to us by some of our tenants. Other Assets, Net. Other assets consist principally of deferred financing fees, deferred leasing costs, capitalized lease incentives and prepaid property operating expenses. Deferred financing fees include issuance costs related to borrowings and are capitalized and amortized over the terms of the respective loans. Deferred leasing costs include brokerage, legal and other fees associated with the successful negotiation of leases and are amortized on a straight line basis over the terms of the respective leases. Capitalized lease incentives are amortized on a straight line basis against rental income over the terms of the respective leases. Derivative Instruments. Derivative instruments are recognized as either assets or liabilities in the consolidated balance sheets at fair value. The accounting for changes in the fair value of a derivative instrument depends on whether such instrument has been designated and qualifies as part of a hedging relationship and, further, on the type of hedging relationship. For those derivative instruments that are designated and qualify as hedging instruments, we must designate the hedging instrument, based upon the exposure being hedged, as a fair value hedge, cash flow hedge or a hedge of a net investment in a foreign operation. As of December 31, 2018, we do not have any interest rate derivatives. We are exposed to certain risks relating to our ongoing business operations. The primary risk managed by using derivative instruments is interest rate risk. Interest rate swaps and caps may be entered into to manage interest rate risk associated with floating rate borrowings. We designate interest rate swaps and caps as cash flow hedges of floating rate borrowings. Revenue Recognition. Rental income from operating leases, which includes rent concessions (including free rent and other lease incentives) and scheduled increases in rental rates during the lease term, is recognized on a straight line basis over the life of the lease agreements. We defer the recognition of contingent rental income, such as percentage rents, until the specific targets that trigger the contingent rental income are achieved. Tenant reimbursements and other income includes property level operating expenses reimbursed by our tenants, as well as other incidental revenues, which are recorded as expenses are incurred. Allowance for Doubtful Accounts. We maintain an allowance for doubtful accounts for estimated losses resulting from the inability or unwillingness of certain tenants to make payments required under their leases. The computation of the allowance is based on the tenants' payment histories and current credit profiles, as well as other considerations. Share-Based Compensation. All share-based compensation is measured at fair value on the grant date or date of modification, as applicable, and recognized in earnings over the requisite service period. Depending upon the settlement terms of the awards, all or a portion of the fair value of share-based awards may be presented as a liability or as equity in the consolidated balance sheets. Earnings Per Common Share. Earnings per common share, or EPS, is computed using the weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if our series D convertible preferred shares, our restricted share units (RSUs) or beneficial interests in the Operating Trust (LTIP Units) were converted into our common shares, which could result in a lower EPS amount. The effect of our series D convertible preferred shares on net income attributable to common shareholders is anti-dilutive for all periods presented. Reclassifications. Reclassifications have been made to the prior years' financial statements and notes to conform to the current year's presentation. Legal Matters. We are or may become a party to various legal proceedings. We are not currently involved in any litigation nor, to our knowledge, is any litigation threatened against us where the outcome would, in our judgment based on information currently available to us, have a material adverse effect on the Company. Income Taxes. We are a REIT under the Internal Revenue Code of 1986, as amended, and are generally not subject to federal and state income taxes provided we distribute our taxable income to our shareholders and meet other requirements for qualifying as a REIT. We are also subject to certain state and local taxes without regard to our REIT status. The Income Taxes Topic of the FASB ASC prescribes how we should recognize, measure and present in our financial statements uncertain tax positions that have been taken or are expected to be taken in a tax return. Deferred tax assets are recognized to the extent that it is "more likely than not" that a particular tax position will be sustained upon examination or audit. To the extent the "more likely than not" standard has been satisfied, the benefit associated with a tax position is measured as the largest amount that has a greater than 50% likelihood of being realized upon settlement. We classify interest and penalties related to uncertain tax positions, if any, in our financial statements as a component of general and administrative expense. Use of Estimates. Preparation of these financial statements in conformity with U.S. generally accepted accounting principles, or GAAP, requires us to make estimates and assumptions that may affect the amounts reported in these financial statements and related notes. The actual results could differ from these estimates. New Accounting Pronouncements. In August 2018, the FASB issued Accounting Standards Update (ASU) 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which changes the fair value measurement disclosure requirements of ASC 820. This update is effective for fiscal years beginning after December 15, 2019, and for interim periods within those fiscal years. We do not expect the adoption of ASU 2018-13 to have a material impact on our consolidated financial statements. In June 2018, the FASB issued ASU 2018-07, Improvements to Nonemployee Share-Based Payment Accounting, which simplifies the accounting for share-based payments granted to nonemployees for goods and services. This update is effective for fiscal years beginning after December 15, 2018, and for interim periods within those fiscal years. We do not expect the adoption of ASU 2018-07 to have a material impact on our consolidated financial statements. In May 2017, the FASB issued ASU 2017-09 Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting. ASU 2017-09 is designed to provide clarity and reduce both (1) diversity in practice and (2) cost and complexity when applying the guidance in Topic 718, to a change to the terms or conditions of a share-based payment award. ASU 2017-09 is effective for fiscal years beginning after December 15, 2017. We adopted ASU 2017-09 on January 1, 2018, and the adoption did not have a material impact on our consolidated financial statements. In February 2017, the FASB issued ASU 2017-05 Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets. ASU 2017-05 is designed to provide guidance on how to recognize gain and losses on sales, including partial sales, of nonfinancial assets to noncustomers. We adopted ASU 2017-05 on January 1, 2018 and the adoption did not have a material impact on our consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires more timely recognition of credit losses associated with financial assets. This update is effective for fiscal years beginning after December 15, 2019, and for interim periods within those fiscal years. Early adoption is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2018. We are currently evaluating the impact, if any, the adoption of ASU 2016-13 will have 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 parties to a contract (i.e., 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 of the leased asset by the lessee. This classification will determine whether the lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. ASU 2016-02 supersedes previous leasing standards. ASU 2016-02 is effective for us for reporting periods beginning after December 15, 2018, with early adoption permitted. For leases where we are the lessor, we expect to account for these leases using an approach that is substantially equivalent to current guidance. Additionally, under ASU 2016-02 lessors may only capitalize incremental direct leasing costs. For leases in which we are the lessee, we expect to recognize a right-of-use asset and a lease liability equal to the present value of the minimum lease payments with rent expense being recognized on a straight-line basis and the right of use asset being reduced when lease payments are made. In July 2018, the FASB issued ASU 2018-11 to provide entities with relief from the costs of implementing certain aspects of ASU 2016-02. The amendment to the new leases standard includes a practical expedient that provides lessors an option not to separate lease and non-lease components when certain criteria are met and instead account for those components as a single component under the new leases standard. The amendment also provides a transition option that permits the application of the new guidance as of the adoption date rather than to all periods presented. We anticipate electing the practical expedient to account for both our lease and non-lease components as a single component under the leases standard and electing the new transition option. We believe the adoption of these pronouncements will have an immaterial impact on our financial statements, both as a lessor and as a lessee. In January 2016, the FASB issued ASU 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities, related to certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 will require entities to measure their equity investments at fair value and recognize any changes in fair value in net income, with certain exceptions, rather than other comprehensive income. This update is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. We adopted ASU 2016-01 on January 1, 2018 and reclassified a $1.9 million unrealized gain from cumulative other comprehensive loss to cumulative net income on our consolidated balance sheet (see Note 10). In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. The objective of ASU 2014-09, as amended, is to establish a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and will supersede most of the existing revenue recognition guidance, including industry-specific guidance. The core principle is that an entity should recognize revenue to depict the transfer of 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. In applying ASU 2014-09, companies will perform a five-step analysis of transactions to determine when and how revenue is recognized. ASU 2014-09 applies to all contracts with customers except those that are within the scope of other topics in the FASB’s ASC, and more particularly lease contracts with customers, which are a scope exception. ASU 2014-09 is effective for the first interim period within annual reporting periods beginning after December 15, 2017, with early adoption permitted. We adopted ASU 2014-09 on January 1, 2018 and the adoption did not have a material impact on our consolidated financial statements.

Summary of Significant Accounting Policies

Basis of Presentation. The consolidated financial statements include our investments in 100% owned subsidiaries and majority owned subsidiaries that are controlled by us. References to we, us, our and the Company, refer to Equity Commonwealth and its consolidated subsidiaries as of December 31, 2018, unless the context indicates otherwise. All intercompany transactions and balances have been eliminated.

Real Estate Properties. We record real estate properties at cost. We depreciate real estate investments on a straight line basis over estimated useful lives of up to 40 years for buildings and improvements, and up to 12 years for personal property.

Each time we enter into a new lease, or materially modify an existing lease, we evaluate its classification as either a capital or operating lease. The classification of a lease as capital or operating affects the carrying value of a property, as well as our recognition of rental payments as revenue. These evaluations require us to make estimates of, among other things, the remaining useful life and fair market value of a leased property, appropriate discount rates and future cash flows.

We allocate the consideration paid for our properties among land, buildings and improvements and, for properties that qualify as acquired businesses under the Business Combinations Topic of the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC), to identified intangible assets and liabilities, consisting of the value of above market and below market leases, the value of acquired in place leases and the value of tenant relationships. Purchase price allocations and the determination of useful lives are based on our estimates and, under some circumstances, studies from independent real estate appraisal firms to provide market information and evaluations that are relevant to our purchase price allocations and determinations of useful lives; however, we are ultimately responsible for the purchase price allocations and determination of useful lives.

We allocate the consideration to land, buildings and improvements based on a determination of the fair values of these assets assuming the property is vacant. We determine the fair value of a property using methods that we believe are similar to those used by independent appraisers. Purchase price allocations to above market and below market leases are based on the estimated present value (using an interest rate which reflects our assessment of the risks associated with the leases acquired) of the difference between (1) the contractual amounts to be paid pursuant to the acquired in place leases and (2) our estimate of fair market lease rates for the corresponding leases, measured over a period equal to the remaining non-cancelable terms of the respective leases. Purchase price allocations to acquired in place leases and tenant relationships are determined as the excess of (1) the purchase price paid for a property after adjusting existing in place leases to estimated market rental rates over (2) the estimated fair value of the property as if vacant. We aggregate this value between acquired in place lease values and tenant relationships based on our evaluation of the specific characteristics of each tenant's lease; however, the value of tenant relationships has not been separated from acquired in place lease value for our properties because we believe such value and related amortization expense is immaterial for acquisitions reflected in our historical financial statements. We consider certain factors in performing these analyses including estimates of carrying costs during the expected lease up periods, including real estate taxes, insurance and other operating income and expenses and costs to execute similar leases in current market conditions, such as leasing commissions, legal and other related costs. If we believe the value of tenant relationships is material in the future, those amounts will be separately allocated and amortized over the estimated lives of the relationships. We recognize the excess, if any, of the consideration paid over amounts allocated to land, buildings and improvements and identified intangible assets and liabilities as goodwill and we recognize gains if amounts allocated exceed the consideration paid.

We amortize capitalized above market lease values (presented in our consolidated balance sheets as acquired real estate leases) as a reduction to rental income over the remaining terms of the respective leases. We amortize capitalized below market lease values as an increase to rental income over the remaining terms of the respective leases. We amortize the value of acquired in place leases exclusive of the value of above market and below market acquired in place leases to expense over the remaining terms of the respective leases. If a lease is terminated prior to its stated expiration, the unamortized lease intangibles relating to that lease is written off.

We review our properties for impairment quarterly, or whenever events or changes in circumstances indicate that their carrying amounts may not be recoverable. Impairment indicators may include our decision to dispose of an asset before the end of its estimated useful life, declining tenant occupancy, lack of progress releasing vacant space, tenant bankruptcies, low long term prospects for improvement in property performance, weak or declining tenant profitability, and cash flow or liquidity. When indicators of potential impairment are present that suggest that the carrying amounts of real estate assets may not be recoverable, we assess the recoverability of these assets by determining whether the respective carrying values will be recovered through the estimated undiscounted future operating cash flows expected from the use of the assets and their eventual disposition. The determination of undiscounted cash flow includes consideration of many factors including income to be earned from the investment over our anticipated hold period, holding costs (exclusive of interest), estimated selling prices, and prevailing economic and market conditions. In the event that such expected undiscounted future cash flows do not exceed the carrying values, we estimate the fair value of the assets and record an impairment charge equal to the amount by which the carrying value exceeds the estimated fair value. Estimated fair values are calculated based on the following information, (i) recent third party estimates of market value, (ii) market prices for comparable properties, or (iii) the present value of future cash flows. During the years ended December 31, 2018, 2017, and 2016 we recorded a loss on asset impairment in continuing operations totaling $12.1 million, $19.7 million and $58.5 million respectively, to reduce the carrying value of properties to their estimated fair values (see Note 15).

When we classify properties as held for sale, we discontinue the recording of depreciation expense and estimate their fair value less costs to sell. If we determine that the carrying value for these properties exceed their estimated fair value less costs to sell, we record a loss on asset impairment.

Certain of our real estate assets contain hazardous substances, including asbestos. We believe any asbestos in our buildings is contained in accordance with current regulations. If we remove the asbestos or renovate or demolish these properties, certain environmental regulations govern the manner in which the asbestos must be handled and removed. We do not believe that there are other environmental conditions or issues at any of our properties that have had or will have a material adverse effect on us. However, no assurances can be given that conditions or issues are not present at our properties or that costs we may be required to incur in the future to remediate contamination or comply with environmental, health and safety laws will not have a material adverse effect on our business or financial condition. As of December 31, 2018 and 2017, we did not have any accrued environmental remediation costs.

Cash and Cash Equivalents. Our cash and cash equivalents consist of cash maintained in time deposits, depository accounts and money market accounts. We continually monitor the credit ratings of the financial institutions holding our deposits to minimize our exposure to credit risk. Throughout the year, we have cash balances in excess of federally insured limits deposited with various financial institutions. We do not believe we are exposed to any significant credit risk on cash and cash equivalents.

Marketable Securities. All of our marketable securities are classified as available-for-sale and consisted of United States Treasury notes and common stock. Available-for-sale securities are presented on our consolidated balance sheets at fair value. Changes in values of the United States Treasury notes are recognized in cumulative other comprehensive loss. Realized gains and losses are recognized in earnings only upon the sale of the United States Treasury notes. Changes in values of common stock prior to their sale in March 2018, were recognized in interest and other income, net on the consolidated statements of operations.

We evaluate our marketable securities for impairment each reporting period. For securities 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. To the extent an other-than-temporary impairment is deemed to have occurred, an impairment charge is recorded and a new cost basis is established.

Restricted Cash. Restricted cash consists of amounts escrowed for future real estate taxes, insurance, leasing costs, capital expenditures and debt service, as required by our mortgage debt, as well as security deposits paid to us by some of our tenants.

Other Assets, Net. Other assets consist principally of deferred financing fees, deferred leasing costs, capitalized lease incentives and prepaid property operating expenses. Deferred financing fees include issuance costs related to borrowings and are capitalized and amortized over the terms of the respective loans. Deferred leasing costs include brokerage, legal and other fees associated with the successful negotiation of leases and are amortized on a straight line basis over the terms of the respective leases. Capitalized lease incentives are amortized on a straight line basis against rental income over the terms of the respective leases.

Derivative Instruments. Derivative instruments are recognized as either assets or liabilities in the consolidated balance sheets at fair value. The accounting for changes in the fair value of a derivative instrument depends on whether such instrument has been designated and qualifies as part of a hedging relationship and, further, on the type of hedging relationship. For those derivative instruments that are designated and qualify as hedging instruments, we must designate the hedging instrument, based upon the exposure being hedged, as a fair value hedge, cash flow hedge or a hedge of a net investment in a foreign operation. As of December 31, 2018, we do not have any interest rate derivatives.

We are exposed to certain risks relating to our ongoing business operations. The primary risk managed by using derivative instruments is interest rate risk. Interest rate swaps and caps may be entered into to manage interest rate risk associated with floating rate borrowings. We designate interest rate swaps and caps as cash flow hedges of floating rate borrowings.

Revenue Recognition. Rental income from operating leases, which includes rent concessions (including free rent and other lease incentives) and scheduled increases in rental rates during the lease term, is recognized on a straight line basis over the life of the lease agreements. We defer the recognition of contingent rental income, such as percentage rents, until the specific targets that trigger the contingent rental income are achieved. Tenant reimbursements and other income includes property level operating expenses reimbursed by our tenants, as well as other incidental revenues, which are recorded as expenses are incurred.

Allowance for Doubtful Accounts. We maintain an allowance for doubtful accounts for estimated losses resulting from the inability or unwillingness of certain tenants to make payments required under their leases. The computation of the allowance is based on the tenants' payment histories and current credit profiles, as well as other considerations.

Share-Based Compensation. All share-based compensation is measured at fair value on the grant date or date of modification, as applicable, and recognized in earnings over the requisite service period. Depending upon the settlement terms of the awards, all or a portion of the fair value of share-based awards may be presented as a liability or as equity in the consolidated balance sheets.

Earnings Per Common Share. Earnings per common share, or EPS, is computed using the weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if our series D convertible preferred shares, our restricted share units (RSUs) or beneficial interests in the Operating Trust (LTIP Units) were converted into our common shares, which could result in a lower EPS amount. The effect of our series D convertible preferred shares on net income attributable to common shareholders is anti-dilutive for all periods presented.

Reclassifications. Reclassifications have been made to the prior years' financial statements and notes to conform to the current year's presentation.

Legal Matters. We are or may become a party to various legal proceedings. We are not currently involved in any litigation nor, to our knowledge, is any litigation threatened against us where the outcome would, in our judgment based on information currently available to us, have a material adverse effect on the Company.

Income Taxes. We are a REIT under the Internal Revenue Code of 1986, as amended, and are generally not subject to federal and state income taxes provided we distribute our taxable income to our shareholders and meet other requirements for qualifying as a REIT. We are also subject to certain state and local taxes without regard to our REIT status.

The Income Taxes Topic of the FASB ASC prescribes how we should recognize, measure and present in our financial statements uncertain tax positions that have been taken or are expected to be taken in a tax return. Deferred tax assets are recognized to the extent that it is "more likely than not" that a particular tax position will be sustained upon examination or audit. To the extent the "more likely than not" standard has been satisfied, the benefit associated with a tax position is measured as the largest amount that has a greater than 50% likelihood of being realized upon settlement. We classify interest and penalties related to uncertain tax positions, if any, in our financial statements as a component of general and administrative expense.

Use of Estimates. Preparation of these financial statements in conformity with U.S. generally accepted accounting principles, or GAAP, requires us to make estimates and assumptions that may affect the amounts reported in these financial statements and related notes. The actual results could differ from these estimates.

New Accounting Pronouncements. In August 2018, the FASB issued Accounting Standards Update (ASU) 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which changes the fair value measurement disclosure requirements of ASC 820. This update is effective for fiscal years beginning after December 15, 2019, and for interim periods within those fiscal years. We do not expect the adoption of ASU 2018-13 to have a material impact on our consolidated financial statements.

In June 2018, the FASB issued ASU 2018-07, Improvements to Nonemployee Share-Based Payment Accounting, which simplifies the accounting for share-based payments granted to nonemployees for goods and services. This update is effective for fiscal years beginning after December 15, 2018, and for interim periods within those fiscal years. We do not expect the adoption of ASU 2018-07 to have a material impact on our consolidated financial statements.

In May 2017, the FASB issued ASU 2017-09 Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting. ASU 2017-09 is designed to provide clarity and reduce both (1) diversity in practice and (2) cost and complexity when applying the guidance in Topic 718, to a change to the terms or conditions of a share-based payment award. ASU 2017-09 is effective for fiscal years beginning after December 15, 2017. We adopted ASU 2017-09 on January 1, 2018, and the adoption did not have a material impact on our consolidated financial statements.

In February 2017, the FASB issued ASU 2017-05 Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets. ASU 2017-05 is designed to provide guidance on how to recognize gain and losses on sales, including partial sales, of nonfinancial assets to noncustomers. We adopted ASU 2017-05 on January 1, 2018 and the adoption did not have a material impact on our consolidated financial statements.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires more timely recognition of credit losses associated with financial assets. This update is effective for fiscal years beginning after December 15, 2019, and for interim periods within those fiscal years. Early adoption is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2018. We are currently evaluating the impact, if any, the adoption of ASU 2016-13 will have 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 parties to a contract (i.e., 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 of the leased asset by the lessee. This classification will determine whether the lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. ASU 2016-02 supersedes previous leasing standards. ASU 2016-02 is effective for us for reporting periods beginning after December 15, 2018, with early adoption permitted. For leases where we are the lessor, we expect to account for these leases using an approach that is substantially equivalent to current guidance. Additionally, under ASU 2016-02 lessors may only capitalize incremental direct leasing costs. For leases in which we are the lessee, we expect to recognize a right-of-use asset and a lease liability equal to the present value of the minimum lease payments with rent expense being recognized on a straight-line basis and the right of use asset being reduced when lease payments are made.

In July 2018, the FASB issued ASU 2018-11 to provide entities with relief from the costs of implementing certain aspects of ASU 2016-02. The amendment to the new leases standard includes a practical expedient that provides lessors an option not to separate lease and non-lease components when certain criteria are met and instead account for those components as a single component under the new leases standard. The amendment also provides a transition option that permits the application of the new guidance as of the adoption date rather than to all periods presented. We anticipate electing the practical expedient to account for both our lease and non-lease components as a single component under the leases standard and electing the new transition option. We believe the adoption of these pronouncements will have an immaterial impact on our financial statements, both as a lessor and as a lessee.

In January 2016, the FASB issued ASU 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities, related to certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 will require entities to measure their equity investments at fair value and recognize any changes in fair value in net income, with certain exceptions, rather than other comprehensive income. This update is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. We adopted ASU 2016-01 on January 1, 2018 and reclassified a $1.9 million unrealized gain from cumulative other comprehensive loss to cumulative net income on our consolidated balance sheet (see Note 10).

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. The objective of ASU 2014-09, as amended, is to establish a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and will supersede most of the existing revenue recognition guidance, including industry-specific guidance. The core principle is that an entity should recognize revenue to depict the transfer of 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. In applying ASU 2014-09, companies will perform a five-step analysis of transactions to determine when and how revenue is recognized. ASU 2014-09 applies to all contracts with customers except those that are within the scope of other topics in the FASB’s ASC, and more particularly lease contracts with customers, which are a scope exception. ASU 2014-09 is effective for the first interim period within annual reporting periods beginning after December 15, 2017, with early adoption permitted. We adopted ASU 2014-09 on January 1, 2018 and the adoption did not have a material impact on our consolidated financial statements.