Summary of Significant Accounting Policies | Summary of Significant Accounting Policies Interim Unaudited Financial Information The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and should be read in conjunction with the financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2017 , which was filed with the Securities and Exchange Commission ("SEC") on February 22, 2018. Certain information and footnote disclosures normally included in the consolidated financial statements prepared in accordance with GAAP have been omitted from this report on Form 10-Q pursuant to the rules and regulations of the SEC. Results for the interim periods in this report are not necessarily indicative of future financial results and have not been audited by our independent registered public accounting firm. In the opinion of management, the accompanying unaudited condensed consolidated financial statements include all adjustments necessary to present fairly our condensed consolidated financial statements as of September 30, 2018 and 2017 , and for the three and nine months ended September 30, 2018 and 2017 . These adjustments are of a normal recurring nature and consistent with the adjustments recorded to prepare the annual audited consolidated financial statements as of December 31, 2017 . All amounts reflected are in millions except share and per share data. Basis of Presentation The accompanying condensed consolidated financial statements include the accounts of the Company, as well as all wholly-owned subsidiaries and any consolidated variable interest entities. All inter-company balances and transactions have been eliminated in consolidation. Investment in Real Estate Investment in real estate consists of land, buildings, improvements and equipment utilized in our data center operations and land held for future development. Additions and improvements which extend an asset’s useful life or increase its functionality are capitalized and depreciated over the asset’s remaining life. Maintenance and repairs are expensed as incurred. We capitalize project costs related to the development and construction of our data centers including interest, real estate taxes, insurance, and other direct costs. Indirect project costs not clearly related to development and construction are expensed as incurred. Indirect project costs that clearly relate to development and construction are capitalized and allocated to the developments to which they relate. For each development, capitalization begins when we determine that the development is probable and significant development activities are underway. We suspend capitalization at such time as significant development activity ceases, but future development is still probable. We cease capitalization when the developments or other improvements are completed and ready for their intended use, or if the intended use changes such that capitalization is no longer appropriate. Building and related improvements are generally considered ready for their intended use when the designated premises, which could be less than the entire building, is ready for occupancy. When we are the lessee of the property and we are involved in the construction of structural improvements, we are deemed the accounting owner of the leased real estate. At inception, the fair value of the building, excluding land, is recorded as a leasehold asset, and the construction and modification costs to the building that are not funded by us are recorded as a liability which is recorded as lease financing arrangements. As construction progresses, the asset and obligation increase by the cost of the structural improvements, which approximate the fair value. At completion of the construction, if our involvement is deemed to continue, the leasehold asset is placed in service and depreciation commences. Depreciation is calculated using the straight-line method over the estimated useful life of the asset. Useful lives range from nine to thirty years for buildings, three to thirty years for building improvements, and two to twenty years for equipment. Leasehold improvements are amortized over the shorter of the asset’s useful life or the remaining lease term, including renewal options which are reasonably assured, and to the lesser of the fair value or financing arrangement obligation estimated at the end of the lease term. Impairment Losses If events or circumstances indicate that the carrying amount of the real estate investment, including leased real estate investments, may not be recoverable, we make an assessment of the recoverability of the asset, usually at the individual property level, by comparing the carrying amount of the asset to our estimate of the aggregate undiscounted future operating cash flows expected to be generated over the holding period of the asset including its eventual disposition. If the carrying amount, including related real estate intangible assets, exceeds the aggregate undiscounted future operating cash flows, we recognize an impairment loss to the extent the carrying amount exceeds the estimated fair value of the asset. We did not record any impairment losses for the three and nine months ended September 30, 2018 and recorded impairment losses of $54.4 million and $58.0 million for the three and nine months ended September 30, 2017 , respectively, related to our leased data center facilities in the Connecticut markets, and with respect to the nine months ended September 30, 2017, our leased data center facility in Singapore. Business Combinations and Asset Acquisitions We evaluate whether a transaction is a business combination or an asset acquisition by determining whether the set of assets is a business. When substantially all of the fair value of gross assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets, the transaction is accounted for as an asset acquisition. In an asset acquisition, the purchase price paid for assets acquired is allocated between identified tangible and intangible assets acquired based on relative fair value. Transaction costs associated with asset acquisitions are capitalized. When substantially all of the fair value is not concentrated in a group of similar identifiable assets, the set of assets will generally be considered a business and the Company applies the purchase method for business combinations, where all tangible and identifiable intangible assets acquired and all liabilities assumed are recorded at fair value. Any excess purchase price is recorded as goodwill. If the value of the acquisition is greater than the purchase price, a bargain purchase gain would be recorded. Transaction costs associated with business combinations are expensed as incurred. The following discussion applies to our initial determination of fair value and the resulting subsequent accounting which is generally applicable to both asset acquisitions and business combinations. The fair value of any tangible real estate assets acquired is determined by valuing the building as if it were vacant, and the “as-if-vacant” value is then allocated to land, buildings, equipment and improvements. Land values are derived from appraisals, and building values are calculated as replacement cost less depreciation or estimates of the relative fair value of these assets using net operating income capitalization rates, discounted cash flow analysis or similar methods. We determine in-place lease values based on our evaluation of the specific characteristics of each tenant’s lease agreement and by applying a fair value model. The estimates of fair value of in-place leases include an estimate of carrying costs during the expected lease up periods for the respective leasable area considering current market conditions. In estimating fair value of in-place leases, we consider items such as real estate taxes, insurance, leasing commissions, tenant improvements and other operating expenses to execute similar leases as well as projected rental revenue and carrying costs during the expected lease up period. We amortize the value of in-place leases acquired to expense over the approximate weighted average remaining term of the leases, adjusted for projected tenant turnover, on a composite basis. We determine the value of above-market and below-market in-place leases for acquired properties based on the present value (using an interest rate that reflects the risks associated with the leases acquired) of the difference between (1) the contractual amounts to be paid pursuant to the in-place leases and (2) estimates of current market lease rates for the corresponding in-place leases, measured over a period equal to (i) the remaining non-cancellable lease term for above-market leases, or (ii) the remaining non-cancellable lease term plus any fixed rate renewal options for below-market leases. We record the fair value of above-market and below-market leases as intangible assets or liabilities, and amortize them as an adjustment to revenue over the lease term. Due to the heavily negotiated terms of data center leases and their relative shorter-term maturity, the value of above-market or below-market in-place leases generally does not represent a significant portion of the fair value of the related real estate acquired. We determine the value of other contractual rights based on our evaluation of the specific characteristics of the underlying contracts and by applying a fair value model to the projected cash flows or usage rights that considers the timing and risks associated with the cash flows or usage. We amortize the value of finite contractual rights over the remaining contract period. Indefinite-lived contractual rights are not amortized but are evaluated for impairment at least annually. We determine the fair value of assumed debt by calculating the net present value of the scheduled debt service payments using current market-based terms for interest rates for debt with similar terms that management believes we could obtain and remaining maturities. Any difference between the fair value and stated value of the assumed debt is recorded as a discount or premium and amortized over the remaining life of the loan. Cash and Cash Equivalents and Restricted Cash Cash and cash equivalents include all non-restricted cash held in financial institutions and other non-restricted highly liquid short-term investments with original maturities of three months or less. Restricted cash includes cash equivalents held in our name to collateralize standby letters of credit or its use is restricted by contract or regulation. Equity Investment Our equity investment, which does not qualify for equity method accounting, is classified as “available for sale” and is carried at fair value. Effective beginning January 1, 2018, changes in the fair value are reported as a component of net income (loss). Prior to January 1, 2018, such changes in fair value were reported as a component of comprehensive income (loss). See “ Recently Adopted Accounting Pronouncements ” section below. Dividends paid from operating profits are reported as a component of net income (loss), while other dividends are reported as a return of capital. Rent and Other Receivables Receivables consist principally of trade receivables from customers with expected credit losses recorded as an allowance for doubtful accounts. The allowance for doubtful accounts is estimated based upon historic patterns of credit losses for aged receivables as well as specific provisions for certain identifiable, potentially uncollectible balances. Deferred Leasing and Other Contract Costs Deferred leasing costs include leasing commissions to third party brokers, incremental commissions to employees and external and internal legal costs, which are capitalized and amortized over the term of the customer lease. Deferred leasing costs are presented in other assets and amortization of deferred leasing costs is presented in depreciation and amortization expense. If a lease terminates prior to the expiration of the lease, the remaining unamortized cost is written off to amortization expense. Incremental commission costs paid in obtaining managed service contracts are amortized based on the transfer of goods or services to which the costs relate. The amortization expense is recognized over the contract term. Deferred Financing Costs Deferred financing costs include legal and bank issuance costs incurred in connection with issuance of debt, including costs associated with the issuance of our credit facility, and are presented as a direct reduction from the carrying amount of debt. These financing costs are deferred and amortized to expense over the term of the debt and are included as a component of interest expense. When debt is paid prior to its scheduled maturity date, or the underlying terms are materially modified, the remaining carrying value of deferred finance costs, along with certain other payments to lenders, is included in loss on early extinguishment of debt. Deferred Revenue and Prepaid Rents Deferred revenue is recorded when a customer makes a contractual payment in excess of revenues recognized in accordance with GAAP. Prepaid rent liability is recorded when a customer makes an advance payment or they are contractually obligated to pay any amounts in advance of the associated lease or service period. Revenue Recognition We adopted the new revenue recognition standard effective January 1, 2018. The information in this section describes our current revenue recognition policies. See the section below “ Recently Adopted Accounting Pronouncements ” for additional information related to the adoption. Our revenue primarily consists of colocation lease revenue, metered power reimbursements, managed services, equipment sales, and other services. We generally are not entitled to reimbursements for real estate taxes, insurance or other operating expenses. The colocation lease revenue and metered power reimbursements are recognized under the lease accounting standard and managed services, equipment sales, installations, and other services are recognized under the revenue accounting standard. Payment terms generally range from 30 to 120 days. An allowance for doubtful accounts is recognized when the collection of contractual rent, straight-line rent or customer reimbursements is deemed to be unlikely. Colocation Lease Revenue and Metered Power Reimbursements Colocation lease revenues are generally billed monthly in advance based on the leased space or contracted power. Some contracts have an initial free rent period or payments that escalate over the term of the contract. If rents escalate without the lessee gaining access to or control over additional leased space or power, at the beginning of the lease term, the rental payments are recognized as revenue on a straight-line basis over the term of the lease. If rents escalate because the lessee gains access to and control over additional leased space and power, revenue is recognized in proportion to the additional space or power in the periods that the lessee has control over the use of the additional space or power. The excess of revenue recognized over amounts contractually due is recognized as a straight-line receivable, which is included in other assets in our consolidated balance sheet. When a customer makes an advance payment or they are contractually obligated to pay amounts in advance of the associated lease period, a prepaid rent liability is recorded. When a customer makes a contractual payment in excess of revenues recognized in accordance with GAAP, a deferred revenue liability is recorded. This deferred revenue liability is generally recognized on a straight-line basis over the expected term of the lease, unless the pattern of service suggests otherwise. Some of our leases are structured on a full-service gross basis in which the customer pays a fixed amount for both colocation rent and power. The revenue for these types of leases is recorded in colocation lease revenue. Other leases provide that the customer will be separately billed for power based upon actual, metered usage. Some leases that include billing for metered power include an administrative fee that is charged to the customer. Metered power reimbursement revenue is generally billed one month in arrears, and an estimate of this revenue is accrued in the month that the associated power is provided. Managed Services Managed services include the provisioning of a full-service managed data center, monitoring customer computer equipment, managing backups and storage, utilization reporting and other related ancillary information technology services. Management service contracts generally range from one to five years. Revenue is measured based on the consideration specified in the contract and recognized over time as we satisfy the performance obligation. Equipment sales Equipment sold by us generally consists of servers, switches, networking equipment, cable infrastructure, and cabinets. Revenue is recognized at a point-in-time when control of the equipment transfers to the customer from the Company, which is deemed to take place upon delivery to the customer. Other services Other services are generally one-time services and include installation of customer equipment, performing customer system re-boots, server cabinet and cage management, power monitoring, shipping and receiving, resolving technical issues, and other non-recurring hands-on service requested by the customer. Installation services include mounting, wiring, and testing of customer owned equipment. The installation period is typically short term in nature, and accordingly, revenue from the installation of customer equipment will be recognized at a point-in-time once the installation is complete and the performance obligation is satisfied. Revenue from other services is recognized over time as the Company performs the service as the customer is determined to consume the benefits of the service as the Company performs. As allowed under GAAP, we have adopted the practical expedient that allows us not to disclose information about remaining performance obligations that have original expected durations of one year or less, the amount of the transaction price allocated to the remaining performance obligations and when we expect to recognize that amount as revenue for the year. We have also adopted the “as invoiced” practical expedient, whereby the Company recognizes revenue in the amount that directly corresponds to the amount of value transferred to the customer. Transaction, Acquisition, Integration and Other Related Expenses Transaction expenses represent incremental legal, accounting and professional fees incurred in connection with business combinations and the non-recurring, incremental expenses incurred after a business combination or asset acquisition. These expenditures are expensed as incurred and do not include any recurring costs from our ongoing operations. Income Taxes We have elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (“the Code") and have qualified as a REIT since the year ended December 31, 2013. To qualify as a REIT, we must meet a number of organizational and operational requirements, including a requirement that we distribute at least 90% of our "REIT taxable income", as defined by the Code, to our stockholders. As a REIT, we generally will not be subject to federal income tax at the corporate level, however, we are still subject to foreign, state and local income taxes in the locations in which we conduct business. We intend to operate in such a manner as to continue to qualify as a REIT, but no assurance can be given that we will operate in a manner so as to remain qualified as a REIT. If we fail to qualify as a REIT in any taxable year, we would be subject to federal income tax on our taxable income at regular corporate tax rates. As of September 30, 2018, we believe we are in compliance with all applicable REIT requirements. Since the year ended December 31, 2013, we have conducted certain non-REIT activities through taxable REIT subsidiaries (each, a "TRS"). Income recognized by our TRSs is subject to applicable federal, foreign, state, and local income and margin taxes. We have no significant taxes associated with our TRSs for the periods ended September 30, 2018 or 2017 . Deferred Income Taxes Deferred income taxes represent the tax effect of temporary differences between the book and tax basis of assets and liabilities. As of September 31, 2018, we have a $68.7 million deferred tax liability, included in the Consolidated Balance Sheet for foreign income taxes associated with the Zenium acquisition. See Note 4. Investment in Real Estate for further discussion. As of December 31, 2017, we had no deferred tax liability. We recognize the financial statement benefit of an uncertain tax position only after determining that the relevant tax authority would more likely than not sustain the position following an audit. As of September 30, 2018 , we had no significant uncertain tax positions. Foreign Currency Translation and Transactions Gains or losses from translation of foreign operations where the local currency is the functional currency are included as components of other comprehensive income (loss). The financial position of foreign subsidiaries is translated at the exchange rates in effect at the end of the period, while revenues and expenses are translated at average exchange rates during the period. Gains or losses from foreign currency transactions are included in determining net income. Stock-Based Compensation Expense We have a stock-based incentive award plan for our employees and directors. Stock-based compensation expense associated with these awards is recognized in general and administrative expenses in our consolidated statements of operations. We measure stock-based compensation at the estimated fair value on the grant date and recognize the amortization of stock-based compensation expense over the requisite service period. Fair value is determined based on assumptions related to volatility, interest rates and our market and company performance. Income (Loss) Per Share Basic earnings per share is calculated by dividing net income by the weighted average number of common shares outstanding during the period excluding any unvested securities or unexercised options. Diluted earnings per share is calculated by adjusting basic earnings per share for the dilutive effect of the assumed exercise of securities and options, including the effect of shares issuable under our stock-based incentive plans. Our unvested share-based awards are considered participating securities and are reflected in the calculation of diluted earnings per share. During periods of net loss, the assumed exercise of securities and options is anti-dilutive and is not included in the calculation of earnings per share. For the three months ended September 30, 2018 and for the three and nine months ended September 30, 2017 , any common stock equivalents were anti-dilutive. Business Segments Our data centers have similar economic characteristics and customers across all geographic locations, and our service offerings and delivery of services are provided in a similar manner, using the same types of facilities and similar technologies. Our chief operating decision maker, the Company's Chief Executive Officer, reviews our financial information on an aggregate basis. As a result, we have concluded that we have one reportable business segment. One customer, a Fortune 500 company, represented approximately 19% and 18% of our revenue for the nine months ended September 30, 2018 and 2017 , respectively. Revenue from properties were $206.6 million and $175.3 million for the three months ended September 30, 2018 and 2017 , respectively. Revenues from properties were $600.1 million and $491.5 million for the nine months ended September 30, 2018 and 2017 , respectively. We had net investment in real estate of $4.1 billion and $3.1 billion , at September 30, 2018 and December 31, 2017, respectively. Revenue from non-U.S. properties was not material for the three and nine months ended September 30, 2018 . Use of Estimates Preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. These estimates and assumptions are based on management’s knowledge of current events and actions that we may undertake in the future. Significant estimates include and are related to determining lease terms and revenue recognition, the fair value for purchase price allocations for business combinations and asset acquisitions, and the useful lives of real estate and other long-lived assets. Actual results may differ from these estimates and assumptions. Reclassifications Certain financial information has been revised to conform to the current year presentation due to changes in the significance of the particular activity. The following items have been reclassified: Balance Sheet as of December 31, 2017 • Land related to construction in progress ( $8.7 million ) and land held for future development ( $63.8 million ) were previously included in investment in real estate - land ( $72.5 million ). • Notes receivable and long-term installment contracts are classified within other assets. These items were previously included in rent and other receivables ( $3.3 million ). • Construction costs payable are classified in a separate liability and were previously included in accounts payable and accrued expenses ( $115.5 million ). • Dividends payable are classified in a separate liability and were previously included in accounts payable and accrued expenses ( $41.8 million ). • Lease finance arrangements are classified in capital lease obligations and lease financing arrangements. These items were previously included in a separate line for lease finance arrangements ($ 131.9 million ). • Equity investment is classified in a separate asset account and was previously included in other assets ( $175.6 million ). Statement of Cash Flows for the period ended September 30, 2017 • The cash flow effect of the change in interest accrual is classified within accounts payable and accrued expenses. These items were previously combined with non-cash interest expense, net in the comparable prior year period ( $1.3 million ). • Debt issuance and debt extinguishment costs are classified within proceeds from debt, net. These items were previously included in separate lines, debt issuance costs ( $13.6 million ) and payment of debt extinguishment costs ( $30.4 million ), in the comparable prior year period. Recently Adopted Accounting Pronouncements On January 1, 2018, we adopted the Financial Accounting Standards Board ("FASB") pronouncement ASU 2014-09 with respect to revenue recognition. The revised guidance outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and superseded prior revenue recognition guidance, including industry-specific revenue guidance. The revised guidance replaced most existing revenue and real estate sale recognition guidance in GAAP. The standard specifically excludes lease contracts, which is our primary recurring revenue source; however, our revenue accounting for managed services and sales of real estate and equipment will follow the revised guidance. We adopted the new standard using the modified retrospective transition method, where financial statement presentations prior to the date of adoption are not adjusted. Transactions that were not closed as of the adoption date were adjusted to reflect the new standard and we recorded an adjustment to beginning retained earnings of $0.3 million . See Note 3 "Revenue Recognition" for further information regarding the adoption of the new accounting standard, including expanded quantitative and qualitative disclosures regarding revenue recognition. On January 1, 2018, we adopted ASU 2017-05, which requires the derecognition of a business in accordance with ASC 810, Consolidations, including instances in which the business is considered in substance real estate. In cases where a controlling interest in real estate was sold but a noncontrolling interest is retained, we may record a gain or loss related to both the sold and retained interests. The adoption of this standard did not have an impact on our condensed consolidated financial statements, but depending on future transactions, may in the future. On January 1, 2018, we adopted ASU 2016-01 related to equity investments. Equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) are to be measured at fair value with changes in fair value now recognized in net income. Previously changes in fair value for available for sale equity investments were recorded in other comprehensive income (loss). The adoption of the new standard was made through a cumulative-effect adjustment to beginning retained earnings of $75.6 million . Prior financial statement amounts were not adjusted. For the three months ended September 30, 2018 , the unrealized loss on investment was $36.6 million . For the nine months ended September 30, 2018 , the unrealized gain on investment was $106.6 million . New Accounting Pronouncements In August 2018, the SEC issued Securities Act Release No. 33-10532, Disclosure Update and Simplification, which amends certain of its disclosure requirements and is intended to facilitate the disclosure of information to investors and simplify compliance without significantly altering the total mix of information provided to investors. The amendments will become effective on November 5, 2018. Among the amendments is the requirement to present the changes in shareholders’ equity in the interim financial statements (either in a separate statement or footnote) in quarterly reports on Form 10-Q. Based on the effective date of the amendments and Exchange Act Forms Compliance and Disclosure Interpretation Question 105.09 issued by the staff of the SEC’s Division of Corporation Finance on September 25, 2018 and updated on October 4, 2018, the Company’s first presentation of changes in shareholders’ equity will be in its Form 10-Q for the quarter ending March 31, 2019. In August 2018, the FASB issued ASU 2018-15, which clarifies the accounting for implementation costs incurred in a hosting arrangement that is a service contract. Capitalization of these implementation costs are accounted for under the same guidance as implementation costs incurred to develop or obtain internal-use software and recorded as a prepaid asset. These capitalized costs are to be expensed ratably over the hosting arrangement term as operating expense, along with the service fees. The guidance is effective for periods beginning after December 15, 2019. Early adoption is allowed. The Company does not plan to early adopt this guidance and is evaluating the impact of the new standard. In August 2018, the FASB issued ASU 2018-13, which changes the fair value measurement disclosure requirements of ASC 820. Under this ASU, key provisions include new, eliminated and modified disclosure requirements. The guidance is effective for periods beginning after December 15, 2019. Early adoption is allowed. The Company does not plan to early adopt this guidance and is evaluating the impact of the new standard. In June 2018, the FASB issued ASU 2018-07, which simplifies the accounting for share-based payments granted to nonemployees for goods and services. Under this ASU, most of the guidance on such payments to nonemployees would be aligned with the requirements for share-based payments granted to employees. The Company accounts for its share-based payments to our board of director members in the same manner as employees. Other than to our board of director members, the Company does not award share-based payments to any other nonemployees. Therefore, we do not expect this accounting pronouncement to significantly impact our financial statements. The guidance is effective for periods beginning after December 15, 2018. Early adoption is allowed. In February 2016, the FASB issued ASU 2016-02, regarding the accounting for leases for both lessees and lessors. In July 2018, ASU 2016-02 was amended, providing another transition |