Summary of Significant Accounting Policies

(a) Principles of Consolidation and Basis of Presentation

The accompanying consolidated financial statements include all of the accounts of Digital Realty Trust, Inc., the Operating Partnership and the subsidiaries of the Operating Partnership. Intercompany balances and transactions have been eliminated.

The notes to the consolidated financial statements of Digital Realty Trust, Inc. and the Operating Partnership have been combined to provide the following benefits:


•	enhancing investors’ understanding of the Company and the Operating Partnership by enabling investors to view the business as a whole in the same manner as management views and operates the business;


•	eliminating duplicative disclosure and providing a more streamlined and readable presentation since a substantial portion of the disclosure applies to both the Company and the Operating Partnership; and


•	creating time and cost efficiencies through the preparation of one set of notes instead of two separate sets of notes.

There are few differences between the Company and the Operating Partnership, which are reflected in these consolidated financial statements. We believe it is important to understand the differences between the Company and the Operating Partnership in the context of how we operate as an interrelated consolidated company. Digital Realty Trust, Inc.’s only material asset is its ownership of partnership interests of the Operating Partnership. As a result, Digital Realty Trust, Inc. generally does not conduct business itself, other than acting as the sole general partner of the Operating Partnership, issuing public securities from time to time and guaranteeing certain unsecured debt of the Operating Partnership and certain of its subsidiaries and affiliates. Digital Realty Trust, Inc. itself has not issued any indebtedness but guarantees the unsecured debt of the Operating Partnership and certain of its subsidiaries and affiliates, as disclosed in these notes.

The Operating Partnership holds substantially all the assets of the Company and holds the ownership interests in the Company’s joint ventures. The Operating Partnership conducts the operations of the business and is structured as a partnership with no publicly traded equity. Except for net proceeds from public equity issuances by Digital Realty Trust, Inc., which are generally contributed to the Operating Partnership in exchange for partnership units, the Operating Partnership generally generates the capital required by the Company’s business primarily through the Operating Partnership’s operations, by the Operating Partnership’s or its affiliates’ direct or indirect incurrence of indebtedness or through the issuance of partnership units.

The presentation of noncontrolling interests in operating partnership, stockholders’ equity and partners’ capital are the main areas of difference between the consolidated financial statements of Digital Realty Trust, Inc. and those of the Operating Partnership. The common limited partnership interests held by the limited partners in the Operating Partnership are presented as limited partners’ capital within partners’ capital in the Operating Partnership’s consolidated financial statements and as noncontrolling interests in operating partnership within equity in Digital Realty Trust, Inc.’s consolidated financial statements. The common and preferred partnership interests held by Digital Realty Trust, Inc. in the Operating Partnership are presented as general partner’s capital within partners’ capital in the Operating Partnership’s consolidated financial statements and as preferred stock, common stock, additional paid-in capital and accumulated dividends in excess of earnings within stockholders’ equity in Digital Realty Trust, Inc.’s consolidated financial statements. The differences in the presentations between stockholders’ equity and partners’ capital result from the differences in the equity issued at the Digital Realty Trust, Inc. and the Operating Partnership levels.

To help investors understand the significant differences between the Company and the Operating Partnership, these consolidated financial statements present the following separate sections for each of the Company and the Operating Partnership:


•	consolidated face financial statements; and


•	the following notes to the consolidated financial statements:


•	"Debt of the Company" and "Debt of the Operating Partnership";


•	"Income per Share" and "Income per Unit";


•	"Equity and Accumulated Other Comprehensive Loss, Net of the Company" and Capital and Accumulated Other Comprehensive Loss of the Operating Partnership"; and


•	"Quarterly Financial Information".

In the sections that combine disclosure of Digital Realty Trust, Inc. and the Operating Partnership, these notes refer to actions or holdings as being actions or holdings of the Company. Although the Operating Partnership is generally the entity that enters into contracts and joint ventures and holds assets and debt, reference to the Company is appropriate because the business is one enterprise and the Company generally operates the business through the Operating Partnership.

(b) Cash Equivalents

For the purpose of the consolidated statements of cash flows, we consider short-term investments with original maturities of 90 days or less to be cash equivalents. As of December 31, 2018 and 2017, cash equivalents consist of investments in money market instruments. Financial instruments which potentially subject the Company to concentration of credit risk consist of cash and cash equivalents held in denominations subject to economic uncertainty and exchange rate volatility, such as Brazil.

Investments in real estate are stated at cost, less accumulated depreciation and amortization. Land is not depreciated. Depreciation and amortization are recorded on a straight-line basis over the estimated useful lives as follows:



Acquired ground leases		Terms of the related lease
Buildings and improvements		5-39 years
Machinery and equipment		7-15 years
Furniture and fixtures		3-5 years
Leasehold improvements		Shorter of the estimated useful lives or the terms of the related leases
Tenant improvements		Shorter of the estimated useful lives or the terms of the related leases

Improvements and replacements are capitalized when they extend the useful life, increase capacity, or improve the efficiency of the asset. Repairs and maintenance are charged to expense as incurred.

Assets that are classified as held for sale are recorded at the lower of their carrying value or fair value less costs to dispose. We classify an asset as held for sale once management has the authority to approve and commits to a plan to sell, the asset is available for immediate sale, an active program to locate a buyer has commenced and the sale of the asset is probable and transfer of the asset is expected to occur within one year. Upon the classification of assets as held for sale or sold, the depreciation and amortization of the assets will cease.

(d) Investments in Unconsolidated Joint Ventures

The Company’s investments in unconsolidated joint ventures are accounted for using the equity method, whereby our investment is increased for capital contributed and our share of the joint venture's net income and decreased by distributions we receive and our share of any losses of the joint ventures. We do not record losses of the joint ventures in excess of our investment balances unless we are liable for the obligations of the joint venture or are otherwise committed to provide financial support to the joint venture. Likewise, and as long as we have no explicit or implicit obligations to the joint venture, we will suspend equity method accounting to the extent that cash distributions exceed our investment balances until those unrecorded earnings exceed the excess distributions previously recognized in income. In this case, we will apply cost accounting concepts which tie income recognition to the receipt of cash. Cost basis accounting concepts will apply until earnings exceed the excess distributions previously recognized in income.

We amortize the difference between the cost of our investment in the joint ventures and the book value of the underlying equity into income on a straight-line basis consistent with the lives of the underlying assets. The amortization of this difference was immaterial for each of the years ended December 31, 2018, 2017 and 2016.

(e) Impairment of Long-Lived and Finite-Lived Intangible Assets

We review each of our properties for indicators that its carrying amount may not be recoverable. Examples of such indicators may include a significant decrease in the market price of the property, a change in the expected holding period for the property, a significant adverse change in how the property is being used or expected to be used based on the underwriting at the time of acquisition, an accumulation of costs significantly in excess of the amount originally expected for the acquisition or development of the property, or a history of operating or cash flow losses of the property. When such impairment indicators exist, we review an estimate of the future undiscounted net cash flows (excluding interest charges) expected to result from the real estate investment’s use and eventual disposition and compare that estimate to the carrying value of the property. We consider factors such as future operating income, trends and prospects, as well as the effects of leasing demand, competition and other factors. If our future undiscounted net cash flow evaluation indicates that we are unable to recover the carrying value of a real estate investment, an impairment loss is recorded to the extent that the carrying value exceeds the estimated fair value of the property. These losses have a direct impact on our net income because recording an impairment loss results in an immediate negative adjustment to net income. The evaluation of anticipated cash flows is highly subjective and is based in part on assumptions regarding future occupancy, rental rates and capital requirements that could differ materially from actual results in future periods. Since cash flows on properties considered to be long-lived assets to be held and used are considered on an undiscounted basis to determine whether the carrying value of a property is recoverable, our strategy of holding properties over the long-term directly decreases the likelihood of their carrying values not being recoverable and therefore requiring the recording of an impairment loss. If our strategy changes or market conditions otherwise dictate an earlier sale date, an impairment loss may be recognized and such loss could be material. If we determine that the asset fails the recoverability test, the affected assets must be reduced to their fair value.

We generally estimate the fair value of rental properties utilizing a discounted cash flow analysis that includes projections of future revenues, expenses and capital improvement costs that a market participant would use based on the highest and best use of the asset, which is similar to the income approach that is commonly utilized by appraisers. In certain cases, we may supplement this analysis by obtaining outside broker opinions of value.

In considering whether to classify a property as held for sale, the Company considers whether: (i) management has committed to a plan to sell the property; (ii) the property is available for immediate sale in its present condition; (iii) the Company has initiated a program to locate a buyer; (iv) the Company believes that the sale of the property is probable; (v) the Company is actively marketing the property for sale at a price that is reasonable in relation to its current value; and (vi) actions required for the Company to complete the plan indicate that it is unlikely that any significant changes will be made to the plan.

If all the above criteria are met, the Company classifies the property as held for sale. Upon being classified as held for sale, the Company ceases all depreciation and amortization related to the property and it is recorded at the lower of its carrying amount or fair value less cost to sell. The assets and related liabilities of the property are classified separately on the consolidated balance sheets for the most recent reporting period. Only those assets held for sale that constitute a strategic shift that has or will have a major effect on our operations are classified as discontinued operations. To date we have had no property dispositions or assets classified as held for sale that would meet the definition of discontinued operations.

If impairment indicators arise with respect to intangible assets with finite useful lives, we evaluate impairment by comparing the carrying amount of the asset to the estimated future undiscounted net cash flows expected to be generated by the asset. If estimated future undiscounted net cash flows are less than the carrying amount of the asset, then we estimate the fair value of the asset and compare the estimated fair value to the intangible asset’s carrying value. We recognize any shortfall from carrying value as an impairment loss in the current period.

(f) Purchase Accounting

Purchase accounting is applied to the assets and liabilities related to all real estate investments acquired from third parties. The Company evaluates the nature of the purchase to determine whether the purchase is a business combination or an asset acquisition. Transaction costs associated with business combinations are expensed as incurred while transaction costs associated with an asset acquisition are included in the total costs of the acquisition and are allocated on a pro-rata basis to the carrying value of the assets and liabilities recognized in connection with the acquisition. The following accounting policies related to valuing the acquired tangible and intangible assets and liabilities are applicable to both business combinations and asset acquisitions. However, in the event the purchase is an asset acquisition, no goodwill or gain is permitted to be recognized. In an asset acquisition, the difference between the sum of the identified tangible and intangible assets and liabilities and the total purchase price (including transactions costs) is allocated to the identified tangible and intangible assets and liabilities on a relative fair value basis. In accordance with current accounting guidance, the fair value of the real estate acquired is allocated to the acquired tangible assets, consisting primarily of land, building and tenant improvements, and identified intangible assets and liabilities, consisting of the value of above-market and below-market leases, value of in-place leases and acquired ground leases and in the case of a business combination, tenant relationship value, based in each case on their fair values. Loan premiums, in the case of above-market rate loans, or loan discounts, in the case of below-market loans, are recorded based on the fair value of any loans assumed in connection with acquiring the real estate.

The fair values of the tangible assets of an acquired property are determined based on comparable land sales for land and replacement costs adjusted for physical and market obsolescence for the improvements. The fair values of the tangible assets of an acquired property are also determined by valuing the property as if it were vacant, and the “as-if-vacant” value is then allocated to land, building and tenant improvements based on management’s determination of the relative fair values of these assets. Management determines the as-if-vacant fair value of a property based on assumptions that a market participant would use, which is similar to methods used by independent appraisers. Factors considered by management in performing these analyses include an estimate of carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases. In estimating carrying costs, management includes real estate taxes, insurance and other operating expenses and estimates of lost rental revenue during the expected lease-up periods based on current market demand. Management also estimates costs to execute similar leases including leasing commissions, tenant improvements, legal and other related costs.

In allocating the fair value of the identified intangible assets and liabilities of an acquired property, above-market and below-market in-place lease values are recorded based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) estimated fair market lease rates from the perspective of a market participant for the corresponding in-place leases, measured, for above-market leases, over a period equal to the remaining non-cancelable term of the lease and, for below-market leases, over a period equal to the initial term plus any below-market fixed rate renewal periods. The leases we have acquired do not currently include any below-market fixed rate renewal periods. The capitalized above-market lease values are amortized as a reduction of rental income over the remaining non-cancelable terms of the respective leases. The capitalized below-market lease values, also referred to as acquired lease obligations, are amortized as an increase to rental income over the initial terms of the respective leases and any below-market fixed rate renewal periods.

In addition to the intangible value for above-market leases and the intangible negative value for below-market leases, there is intangible value related to having tenants leasing space in the purchased property, which is referred to as in-place lease value. Such value results primarily from the buyer of a leased property avoiding the costs associated with leasing the property and also avoiding rent losses and unreimbursed operating expenses during the lease-up period. Factors to be considered by management in its analysis of in-place lease values include an estimate of carrying costs during hypothetical expected lease-up periods considering current market conditions, and costs to execute similar leases. In estimating carrying costs, management includes real estate taxes, insurance and other operating expenses and estimates of lost rental revenue at market rates during the expected lease-up periods, depending on local market conditions. In estimating costs to execute similar leases, management considers leasing commissions, legal and other related expenses. The value of in-place leases is amortized to expense over the remaining initial terms of the respective leases.

The Company uses the excess earnings method to value tenant relationship value, if any. Such value exists in transactions that involve the acquisition of tenants and customers that are expected to generate recurring revenues beyond existing in place lease terms. The primary factors to be considered by management in its analysis of tenant relationship value include historical tenant lease renewals and attrition rates, rental renewal probabilities and related market terms, estimated operating costs, and discount rate. Tenant relationship value is amortized to expense ratably over the anticipated life of the tenant relationships generating excess earnings, which is the period management uses to value this intangible asset.

(g) Goodwill

Goodwill represents the excess of the purchase price over the fair value of net tangible and intangible assets acquired and tangible and intangible liabilities assumed in a business combination. Goodwill is not amortized. We perform an annual impairment test for goodwill and between annual tests, we evaluate goodwill for impairment whenever events or changes in circumstances occur that would more likely than not reduce the fair value of a reporting unit below its carrying value. In our impairment tests of goodwill, we first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If based on this assessment, we determine that the fair value of the reporting unit is not less than its carrying value, then performing the additional two-step impairment test is unnecessary. If our qualitative assessment indicates that goodwill impairment is more likely than not, we perform a two-step impairment test. We test goodwill for impairment under the two-step impairment test by first comparing the book value of net assets including goodwill to the fair value of the reporting unit. If the fair value is determined to be less than the book value of the net assets, including goodwill, a second step is performed to compute the amount of impairment as the difference between the implied fair value of goodwill and its carrying value. We estimate the fair value of the reporting unit using discounted cash flows. If the carrying value of goodwill exceeds its implied fair value, an impairment charge is recognized. We have not recognized any goodwill impairments since our inception. Since some of the goodwill is denominated in foreign currencies, changes to the goodwill balance occur over time due to changes in foreign exchange rates.

The following is a summary of goodwill activity for the year ended December 31, 2018 (in thousands):



	Balance as of December 31, 2017		Merger / Acquisition		Impact of Change in Foreign Exchange Rates			Balance as of December 31, 2018
Merger / Portfolio Acquisition

Telx Acquisition	$	330,845	$	—	$	—		$	330,845
European Portfolio Acquisition	466,604		—		(24,255		)	442,349
DFT Merger	2,592,146		—		—			2,592,146
Ascenty Acquisition	—		982,667		—			982,667
Total	$	3,389,595	$	982,667	$	(24,255	)	$	4,348,007

(h) Capitalization of Costs

Direct and indirect project costs that are clearly associated with the development of properties are capitalized as incurred. Project costs include all costs directly associated with the development of a property, including construction costs, interest, property taxes, insurance, legal fees and costs of personnel working on the project. Indirect costs that do not clearly relate to the projects under development are not capitalized and are charged to expense as incurred.

Capitalization of costs begins when the activities necessary to get the development project ready for its intended use begins, which include costs incurred before the beginning of construction. Capitalization of costs ceases when the development project is substantially complete and ready for its intended use. Determining when a development project commences and when it is substantially complete and ready for its intended use involves a degree of judgment. We generally consider a development project to be substantially complete and ready for its intended use upon receipt of a certificate of occupancy. If and when development of a property is suspended pursuant to a formal change in the planned use of the property, we will evaluate whether the accumulated costs exceed the estimated value of the project and write off the amount of any such excess accumulated costs. For a development project that is suspended for reasons other than a formal change in the planned use of such property, the accumulated project costs are evaluated for impairment consistent with our impairment policies for long-lived assets. Capitalized costs are allocated to the specific components of a project that are benefited.

During the years ended December 31, 2018, 2017 and 2016, we capitalized interest of approximately $34.7 million, $21.7 million and $16.3 million, respectively. During the years ended December 31, 2018, 2017 and 2016, we capitalized amounts relating to compensation expense of employees direct and incremental to construction and successful leasing activities of approximately $74.1 million, $77.3 million and $70.7 million, respectively.

(i) Deferred Leasing Costs

Leasing commissions and other direct and indirect costs associated with the acquisition of tenants are capitalized and amortized on a straight-line basis over the terms of the related leases. Deferred leasing costs is included in acquired in-place lease value, deferred leasing costs and intangibles on the consolidated balance sheet and amounted to approximately $322.2 million and $330.9 million, net of accumulated amortization, as of December 31, 2018 and 2017, respectively. Amortization expense on leasing costs was approximately $72.9 million, $50.1 million, and $43.8 million for the years ended December 31, 2018, 2017 and 2016, respectively.

(j) Foreign Currency Translation

Assets and liabilities of our subsidiaries outside the United States with non-U.S. dollar functional currencies are translated into U.S. dollars using exchange rates as of the balance sheet dates. Income and expenses are translated using the average exchange rates for the reporting period. Foreign currency translation adjustments are recorded as a component of other comprehensive income. In the statement of cash flows, cash flows denominated in foreign currencies are translated using the exchange rates in effect at the time of the cash flows or an average exchange rate for the period, depending on the nature of the cash flow item.

(k) Deferred Financing Costs

Loan fees and costs are recorded as an adjustment to the carrying amount of the related debt and amortized over the life of the related loans on a straight-line basis, which approximates the effective interest method. Such amortization is included as a component of interest expense.

(l) Restricted Cash

Restricted cash consists of deposits for real estate taxes and insurance and other amounts as required by our loan agreements including funds for leasing costs and improvements related to unoccupied space.

(m) Offering Costs

Underwriting commissions and other offering costs are reflected as a reduction in additional paid-in capital, or in the case of preferred stock, as a reduction of the carrying value of preferred stock.

(n) Share-Based Compensation

The Company measures all share-based compensation awards at fair value on the date they are granted to employees and directors, and recognizes compensation cost, net of forfeitures, over the requisite service period for awards with only a service condition. The estimated fair value of the long-term incentive units and Class D units (discussed in Note 14) granted by us is being amortized on a straight-line basis over the expected service period.

The fair value of share-based compensation awards that contain a market condition is measured using a Monte Carlo simulation method and not adjusted based on actual achievement of the market condition.

(o) Derivative Instruments

Derivative financial instruments are employed to manage risks, including foreign currency and interest rate exposures and are not used for trading or speculative purposes. As part of the Company’s risk management program, a variety of financial instruments, such as interest rate swaps and foreign exchange contracts, may be used to mitigate interest rate exposure and foreign currency exposure. The Company recognizes all derivative instruments in the balance sheet at fair value.

Changes in the fair value of derivatives are recognized periodically either in earnings or in stockholders’ equity as a component of accumulated other comprehensive income (loss), depending on whether the derivative financial instrument is undesignated or qualifies for hedge accounting, and if so, whether it represents a fair value, cash flow, or net investment hedge. Gains and losses on derivatives designated as cash flow hedges, to the extent they are included in the assessment of effectiveness, are recorded in other comprehensive income (loss) and subsequently reclassified to earnings to offset the impact of the hedged items when they occur. In the event it becomes probable the forecasted transaction to which a cash flow hedge relates will not occur, the derivative would be terminated and the amount in other comprehensive income (loss) would be recognized in earnings. Changes in the fair value of derivatives that are designated and qualify as a hedge of the net investment in foreign operations, to the extent they are included in the assessment of effectiveness, are reported in other comprehensive income (loss) and are deferred until disposal of the underlying assets. Gains and losses representing components excluded from the assessment of effectiveness for cash flow and fair value hedges are recognized in earnings on a straight-line basis in the same caption as the hedged item over the term of the hedge. Gains and losses representing components excluded from the assessment of effectiveness for net investment hedges are recognized in earnings on a straight-line basis over the term of the hedge.

The net interest paid or received on interest rate swaps is recognized as interest expense. Gains and losses resulting from the early termination of interest rate swap agreements are deferred and amortized as adjustments to interest expense over the remaining period of the debt originally covered by the terminated swap.

See Note 15 for further discussion on derivative instruments.

(p) Income Taxes

Digital Realty Trust, Inc. has elected to be treated as a real estate investment trust (a “REIT”) for federal income tax purposes. As a REIT, Digital Realty Trust, Inc. generally is not required to pay federal corporate income tax to the extent taxable income is currently distributed to its stockholders. If Digital Realty Trust, Inc. fails to qualify as a REIT in any taxable year, it will be subject to federal income tax (including any applicable alternative minimum tax for taxable years prior to 2018) on its taxable income.

The Company is subject to foreign, state and local income taxes in the jurisdictions in which it conducts business. The Company’s taxable REIT subsidiaries are subject to federal, state and foreign income taxes to the extent there is taxable income. Accordingly, the Company recognizes current and deferred income taxes.

We assess our significant tax positions in accordance with U.S. GAAP for all open tax years and determine whether we have any material unrecognized liabilities from uncertain tax benefits. If a tax position is not considered “more-likely-than-not” to be sustained solely on its technical merits, no benefits of the tax position are to be recognized (for financial statement purposes). As of December 31, 2018 and 2017, we have no assets or liabilities for uncertain tax positions. We classify interest and penalties from significant uncertain tax positions as interest expense and operating expense, respectively, in our consolidated income statements. For the years ended December 31, 2018, 2017 and 2016, we had no such interest or penalties. The tax year 2015 and thereafter remain open to examination by the major taxing jurisdictions with which the Company files tax returns.

See Note 11 for further discussion on income taxes.

(q) Presentation of Transactional-based Taxes

We account for transactional-based taxes, such as value added tax, or VAT, for our international properties on a net basis.

(r) Redeemable Noncontrolling Interests

Redeemable noncontrolling interests include amounts related to partnership units issued by consolidated subsidiaries of the Company in which redemption for equity is outside the control of the Company. Partnership units which are determined to be contingently redeemable for cash under the Financial Accounting Standards Board’s "Distinguishing Liabilities from Equity" guidance are classified as redeemable noncontrolling interests and presented in the mezzanine section between total liabilities and stockholder’s equity on the Company’s consolidated balance sheets. The amounts of consolidated net income attributable to the Company and to the noncontrolling interests are presented on the Company’s consolidated income statements.

(s) Revenue Recognition

In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers (Topic 606)", and since that date has issued several additional ASUs intended to clarify certain aspects of ASU No. 2014-09 and to provide for certain practical expedients entities may elect upon adoption. Collectively, these ASUs outline a single comprehensive model for entities to use in accounting for revenues arising from contracts with customers. We adopted Topic 606 in the first quarter of 2018 using the modified retrospective transition method and applied Topic 606 to those contracts that were not completed as of January 1, 2018. The results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts are not adjusted and continue to be presented under Topic 605. Our financial statements did not recognize a material effect from the cumulative impact of adopting Topic 606 as the new accounting standard does not impact lessor accounting.

The majority of our revenue is derived from lease arrangements, which we account for in accordance with “Leases (Topic 840)”. We account for the non-lease components within our lease arrangements, as well as other sources of revenue, in accordance with Topic 606. Revenue recognized as a result of applying Topic 840 was 97% and Topic 606 was 3% of total operating revenue for the year ended December 31, 2018.

Our leases are classified as operating leases and minimum rents are recognized on a straight-line basis over the terms of the leases, which may span multiple years. The excess of rents recognized over amounts contractually due pursuant to the underlying leases is included in deferred rent in the accompanying consolidated balance sheets and contractually due but unpaid rents are included in accounts and other receivables.

Tenant reimbursements for real estate taxes, common area maintenance, and other recoverable costs under our leases are recognized in the period that the expenses are incurred. Lease termination fees are recognized over the remaining term of the lease, effective as of the date the lease modification is finalized, assuming collection is not considered doubtful. As discussed above, we recognize amortization of the value of acquired above or below-market tenant leases as a reduction of rental revenue in the case of above-market leases or an increase to rental revenue in the case of below-market leases. During the year ended December 31, 2016, we recognized a non-cash gain on lease termination of approximately $29.2 million, as one of our tenants, as part of a lease termination, conveyed substantially all of its colocation and turn-key improvements to the Company.

Interconnection services are included in rental and other services on the consolidated income statements and are generally provided on a month-to-month, one-year or multi-year term. Interconnection services include port and cross-connect services. Port services are typically sold on a one-year or multi-year term and revenue is recognized on a recurring monthly basis (straight-line). The Company bills customers on a monthly basis and recognizes the revenue over the period the service is provided. Revenue for cross-connect installations is generally recognized in the period the cross-connect is installed. Interconnection services that are not specific to a particular space are accounted for under Topic 606 and have terms that are generally one year or less.

Occasionally, customers engage the Company for certain services. The nature of these services historically involves property management and construction management. The proper revenue recognition of these services can be different, depending on whether the arrangements are service revenue or contractor type revenue.

Service revenues are typically recognized on an equal monthly basis based on the minimum fee to be earned. The monthly amounts could be adjusted depending on if certain performance milestones are met.

Fee income arises primarily from contractual management agreements with entities in which we have a noncontrolling interest. The management fees are recognized as earned under the respective agreements. Management and other fee income related to partially owned noncontrolled entities are recognized to the extent attributable to the unaffiliated interest.

We make subjective estimates as to when our revenue is earned and the collectability of our accounts receivable related to minimum rent, deferred rent, expense reimbursements, lease termination fees and other income. We specifically analyze accounts receivable and historical bad debts, customer concentrations, customer creditworthiness and current economic trends when evaluating the adequacy of the allowance for bad debts. These estimates have a direct impact on our net revenue because a higher bad debt allowance would result in lower net revenue, and recognizing rental revenue as earned in one period versus another would result in higher or lower net revenue for a particular period.

(t) Asset Retirement Obligations

We record accruals for estimated asset retirement obligations as required by current accounting guidance. The amount of asset retirement obligations relates primarily to estimated costs associated with asbestos removal at the end of the economic life of properties that were built before 1984 along with remediation of soil contamination issues. As of December 31, 2018 and 2017, the amount included in accounts payable and other accrued liabilities on our consolidated balance sheets was approximately $17.5 million and $12.5 million, respectively.

(u) Assets and Liabilities Measured at Fair Value

Fair value under U.S. GAAP is a market-based measurement, not an entity-specific measurement. Therefore, our fair value measurements are 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, we use 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 1 and 2 of the hierarchy) and the reporting entity’s own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy).

Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access. Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs for the asset or liability which are typically based on an entity’s own assumptions, as there is little, if any, related market activity. In instances where the determination of the fair-value measurement is based on inputs from different levels of the fair-value hierarchy, the lowest level input that is significant would be used to determine the fair-value measurement in its entirety. Our assessment of the significance of a particular input to the fair-value measurement in its entirety requires judgment, and considers factors specific to the asset or liability.

(v) Transaction and Integration Expense

Transaction and integration expense includes business combination expenses, other business development expenses and other expenses to integrate newly acquired investments, which are expensed as incurred. Transaction expenses include closing costs, broker commissions and other professional fees, including legal and accounting fees related to business combinations or acquisitions that were not consummated. Integration costs include transition costs associated with organizational restructuring (such as severance and retention payments and recruiting expenses), third-party consulting expenses directly related to the integration of acquired companies (in areas such as cost savings and synergy realization, technology and systems work), and internal costs such as training, travel and labor, reflecting time spent by Company personnel on integration activities and projects. Recurring costs are recorded in general and administrative expense.

(w) Gains on Sale of Properties

As of January 1, 2018, we began accounting for the sale of real estate properties under Financial Accounting Standards Board, or FASB, Accounting Standards Update, or ASU, No. 2017-05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20), which provides for revenue recognition based on transfer of ownership. All properties were non-financial real estate assets and thus not businesses which were sold to noncustomers with no performance obligations subsequent to transfer of ownership. During the year ended December 31, 2018, the Company sold real estate properties for gross proceeds of $291.7 million, and a recorded net gain of $80.4 million.

(x) Management’s Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates made. On an on-going basis, we evaluate our estimates, including those related to the valuation of our real estate properties, tenant relationship value, goodwill, contingent consideration, accounts receivable and deferred rent receivable, performance-based equity compensation plans and the completeness of accrued liabilities. We base our estimates on historical experience, current market conditions, and various other assumptions that are believed to be reasonable under the circumstances. Actual results may vary from those estimates and those estimates could vary under different assumptions or conditions.

(y) Segment and Geographic Information

The Company is managed on a consolidated basis based on customer demand considerations. Deployment of capital is geared to satisfy this demand. In this regard, the sale and delivery of our products is consistent throughout the portfolio. Services are provided to customers typical of the data center industry. Rent, and the cost of services are billed and collected. The Company has one operating segment and therefore one reporting segment.

Operating revenues from properties in the United States were $2,482.1 million, $1,942.7 million and $1,670.2 million and outside the United States were $564.4 million, $515.2 million and $442.9 million for the years ended December 31, 2018, 2017 and 2016, respectively. We had investments in real estate located in the United States of $11.1 billion, $10.5 billion and $6.3 billion and outside the United States of $3.8 billion, $3.1 billion and $2.6 billion as of December 31, 2018, 2017 and 2016, respectively.

Operating revenues from properties located in the United Kingdom were $295.3 million, $275.1 million and $234.3 million, or 9.7%, 11.2% and 11.1% of total operating revenues, for the years ended December 31, 2018, 2017 and 2016, respectively. No other foreign country comprised more than 10% of total operating revenues for each of these years. We had investments in real estate located in the United Kingdom of $1.6 billion, $1.7 billion and $1.5 billion, or 10.9%, 12.1% and 16.6% of total investments in real estate, as of December 31, 2018, 2017 and 2016, respectively. No other foreign country comprised more than 10% of total investments in real estate as of each of December 31, 2018, 2017 and 2016.

(z) Reclassifications

Certain reclassifications to prior year amounts have been made to conform to the current year presentation. The Company has revised the presentation in its consolidated income statements for the years ended December 31, 2017 and 2016 to reclassify $235.7 million and $204.3 million from Interconnection and other to Rental and other services, respectively.

(aa) New Accounting Pronouncements

New Accounting Standards Adopted

In August 2017, the FASB issued ASU No. 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities". The new standard amends the hedge accounting recognition and presentation requirements in Accounting Standards Codification, or ASC, 815. As permitted by ASU No. 2017-12, the Company early adopted this standard in the first quarter of 2018 on a prospective basis. Refer to Note 2(o), Derivative Instruments, for our policy related to the adoption of this standard.

In August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments". The new standard provides guidance on the classification in the statement of cash flows of cash distributions received from equity method investments, including unconsolidated joint ventures. The ASU provides two approaches to determine the classification of cash distributions received from equity method investees: (i) the “cumulative earnings” approach, under which distributions up to the amount of cumulative equity in earnings recognized are classified as cash inflows from operating activities, and those in excess of that amount are classified as cash inflows from investing activities, and (ii) the “nature of the distribution” approach, under which distributions are classified based on the nature of the underlying activity that generated cash distributions. An entity could elect either the “cumulative earnings” or the “nature of the distribution” approach. If the “nature of the distribution” approach is elected and the entity lacks the information necessary to apply it in the future, that entity will have to apply the “cumulative earnings” approach as an accounting change on a retrospective basis. We adopted this ASU using the “nature of the distribution” approach and applied it retrospectively, as required by the ASU. We previously presented distributions from our equity method investees by utilizing the “nature of the distribution” approach; therefore, the adoption of this ASU had no effect on our consolidated financial statements.

In January 2016, the FASB issued ASU No. 2016-01, "Recognition and Measurement of Financial Assets and Financial Liabilities". The guidance requires entities to measure equity investments that do not result in consolidation and are not accounted for under the equity method at fair value and to record changes in instruments specific credit risk for financial liabilities measured under the fair value option in other comprehensive income. The principal effect of ASU No. 2016-01 on our consolidated financial statements is that, prior to adoption of ASU No. 2016-01, changes in the fair values of investments in equity securities with readily determinable fair values or redemption values were recognized in other comprehensive income until realized, while under ASU No. 2016-01 all changes in the fair values of these equity securities are recognized in current earnings. The update is effective for fiscal years beginning after December 15, 2017, and for interim periods therein. We adopted this standard in the first quarter of 2018 and the adoption did not have a material impact on our consolidated financial statements.

New Accounting Standards Issued but not yet Adopted

In February 2016, FASB issued ASU No. 2016-02, “Leases”, and since that date has issued several additional ASU’s intended to clarify certain aspects of ASU 2016-02 and to provide certain practical expedients entities can elect upon adoption (collectively, “Topic 842”). Topic 842 sets out the principles for recognition, measurement, presentation, and disclosure of leases for both parties to a lease agreement (i.e., lessees and lessors) and supersedes the previous leases standard, Leases (Topic 840). The standard is effective for the Company on January 1, 2019. Upon adoption of Topic 842, we plan to elect the following practical expedients provided in the standard:


•	Package (“all or nothing” expedients) - requires us not to reevaluate our existing or expired leases as of January 1, 2019, under Topic 842;


•	Optional transition method - requires us to apply Topic 842 prospectively from the effective date of adoption (i.e., January 1, 2019);


•	Land easements - requires us to account for land easements existing as of January 1, 2019, under the accounting standards applied to them prior to January 1, 2019;


•	Lease and non-lease components (lessee) - requires us to account for lease and nonlease components associated with that lease under Topic 842 as a single lease component, for all classes of underlying assets;


•	Lease and non-lease components (lessor) - requires us to account for lease and nonlease components associated with that lease under Topic 842 as a single lease component, if certain criteria are met, for all classes of underlying assets;


•	Short-term leases practical expedient (lessee) - for leases with a term of 12 months or less in which we are the lessee, this expedient requires us not to record on our balance sheets the related lease liabilities and right-of-use assets.

Topic 842 requires use of a modified retrospective transition method. On January 1, 2019 we plan to adopt Topic 842, electing the package of transition practical expedients and the optional transition method to apply the transition provisions from the effective date of adoption. Election of the package of transition practical expedients shall allow us not to reassess the following:


•	Whether any expired or existing contracts as of January 1, 2019 are or contain leases as defined in Topic 842;


•	The lease classification for any expired or existing leases as of January 1, 2019;


•	Treatment of initial direct costs relating to any existing leases as of January 1, 2019.

We shall apply the package of transition practical expedients consistently to all leases (i.e., in which we are a lessee or a lessor) that commenced before January 1, 2019. Election of this expedient permits us to “run off” our leases that commenced before January 1, 2019, for the remainder of their lease terms pursuant to Topic 840 and to apply Topic 842 to leases commencing or modified after January 1, 2019.

In addition, pursuant to our planned election of the land easement practical expedient, in transition we shall continue to account for land easements existing as of January 1, 2019 under the accounting standards applied to them prior to January 1, 2019. Additionally, we do not plan to elect the transition practical expedient to use hindsight in determining the lease term for our leases, existing as of January 1, 2019 and in assessing impairment of right-of-use assets. We acquired Ascenty on December 20, 2018, and management is currently assessing the impact of Topic 842 from both a lessor and lessee perspective.

Lessee accounting

Topic 842 requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle whether the lease transfers control to the lessee, and is in substance, a financed purchase of the underlying asset by the lessee. Topic 842 also requires lessees to record a right-of-use asset and a lease liability for all leases with a term greater than 12 months regardless of their classification. Accounting for leases with a term of 12 months or less will be similar to existing guidance for operating leases under Topic 840. Interest and amortization expense are recognized for finance leases while a single lease expense is recognized for operating leases, on a straight-line basis.

As we plan our election of the package of transition practical expedients, operating and capital leases existing as of January 1, 2019, for which we are the lessee, shall continue to be classified as operating and finance leases, respectively, subsequent to adoption of Topic 842.

In applying the transition provisions to our operating leases, we shall measure lease liabilities at the present value of the sum of remaining minimum rental payments (as defined under Topic 840) using our incremental borrowing rates as of January 1, 2019. We shall measure right-of-use assets for our operating leases at the initial measurement of applicable lease liabilities adjusted for other related lease balances at transition. At January 1, 2019, we estimate we shall recognize the following for our operating leases: lease liabilities between $700.0 million and $900.0 million and right-of-use assets between $625.0 million and $825.0 million.

In applying the transition provisions to our capital leases, at the effective date, we shall measure lease liabilities and right-of-use assets for finance leases at the carrying amount of capital lease obligations and capital lease assets under Topic 840, respectively.

Additionally, we shall apply the transition provisions to build-to-suit leases for which assets and liabilities have been recognized solely as a result of the transactions’ build-to-suit designation in accordance with Topic 840. Therefore, at January 1, 2019 we shall derecognize assets and liabilities for build-to-suit leases where construction had completed, with the difference recorded as an increase to accumulated dividends in excess of earnings at the adoption date. We shall account for these leases from January 1, 2019 following the lessee transition guidance.

Lessor accounting

Under Topic 840 our leases are classified as operating leases, and we recognize rental revenue on a straight-line basis over respective lease terms. Under Topic 840 we consider tenant reimbursements for real estate taxes, common area maintenance, and other recoverable costs as lease components. Generally, we recognize these tenant recoveries as revenue when services are rendered in an amount equal to related operating expenses incurred that are recoverable under the terms of applicable leases. Refer to Note 2(s), Revenue Recognition, for further details on our policies around Revenue Recognition.

For leases entered into on or after January 1, 2019, Topic 842 shall require an entity to identify and separate lease and nonlease components with contract consideration allocated to identified components based on relative stand-alone selling prices. Topic 842 shall govern the recognition of revenue for lease components, and Topic 606 shall govern the recognition of revenue for nonlease components. Under Topic 842, tenant reimbursements for common area maintenance, inclusive of utilities, shall be considered nonlease components. If a lessee makes payments for taxes and insurance directly to a third party on behalf of a lessor, lessors are required to exclude them from variable payments and from recognition in the lessors’ income statements. Otherwise, tenant recoveries for taxes and insurance are classified as additional lease revenue recognized by the lessor on a gross basis in their income statements.

On January 1, 2019, we plan to elect the practical expedient to account for a lease component and nonlease component(s) associated with that lease as a single component if (i) the timing and pattern of transfer of the lease component and the nonlease component(s) associated with it are the same and (ii) the lease component would be classified as an operating lease if it were accounted for separately. If we determine the lease component is the predominant component, we shall account for the single component as an operating lease in accordance with Topic 842. Conversely, we shall account for the combined component under Topic 606 if we determine the nonlease component is the predominant component. We expect operating leases commencing or modified on or after January 1, 2019, for which we are a lessor, shall qualify for the single component practical expedient with the combined component accounted for under Topic 842.

Topic 842 requires lessors to account for leases using an approach that is substantially similar to existing guidance for sales-type leases, direct financing leases and operating leases. Under Topic 842, the criteria to determine whether a lease should be accounted for as a sales-type lease includes the following: (i) ownership is transferred from lessor to lessee by the end of the lease term, (ii) an option to purchase is reasonably certain to be exercised, (iii) the lease term is for the major part of the underlying asset’s remaining economic life, (iv) the present value of lease payments, including any lessee guaranteed residual value, equals or exceeds substantially all of the fair value of the underlying asset, and (v) the underlying asset is specialized and is expected to have no alternative use at the end of the lease term. If any of these criteria is met, a lease is classified as a sales-type lease by the lessor. If none of the criteria are met, a lease may qualify as a direct financing lease or an operating lease. The existence of a residual value guarantee from an unrelated third party other than the lessee may qualify the lease as a direct financing lease by the lessor. Otherwise, the lease is classified as an operating lease by the lessor. We are still evaluating the impact of this standard on its financial statements as a lessor.

Initial direct costs

Topic 842 requires lessees and lessors to capitalize, as initial direct costs, incremental costs of a lease that would not have been incurred if the lease had not been obtained. Effective January 1, 2019, costs we incur to negotiate or arrange a lease regardless of its outcome, such as fixed employee compensation, tax, or legal advice to negotiate lease terms, and costs related to advertising or soliciting potential tenants shall be expensed as incurred.

We estimate approximately $37 million of initial direct costs capitalized in 2018 would have been expensed if Topic 842 had been in effect during 2018. Future expenses as a result of the change in the accounting for initial direct costs shall depend on future events not yet known; therefore, the ultimate impact on initial direct costs from adoption of Topic 842 might differ from our estimate.

As we plan to elect the package of transition practical expedients under Topic 842, we shall not be required to reassess whether initial direct costs capitalized prior to adoption of Topic 842, in connection with leases that commenced prior to January 1, 2019, qualify for capitalization under Topic 842. Therefore, we shall continue to amortize these initial direct costs over corresponding lease terms.

In January 2017, the FASB issued guidance codified in ASU No. 2017-04, "Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment". ASU No. 2017-04 simplifies the accounting for goodwill impairment by eliminating the process of measuring the implied value of goodwill, known as step two, from the goodwill impairment test. Instead, if the carrying amount of a reporting unit exceeds its fair value, an impairment loss shall be recognized in an amount equal to that excess, limited to the total amount of goodwill allocated to that reporting unit. The standard will be effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted. We do not expect the provisions of ASU No. 2017-04 to have a material impact on our consolidated financial statements.

In June 2018, the FASB issued ASU No. 2018-07, “Improvements to Nonemployee Share-Based Payment Accounting,” which more closely aligns the accounting for employee and nonemployee share-based payments. The standard will be effective for interim and annual reporting periods beginning after December 15, 2018. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. We do not expect the provisions of ASU No. 2018-07 to have a material impact on our consolidated financial statements.

In August 2018, the FASB issued ASU No. 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.” This ASU amends existing fair value measurement disclosure requirements by adding, changing, or removing certain disclosures. ASU No. 2018-13 will be effective for us as of January 1, 2020, and earlier adoption is permitted. We are currently reviewing the impact this ASU will have on our financial statements.