Significant Accounting Policies Update (Policies)	9 Months Ended
Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Accounting	The accompanying interim consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information. These financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in the accompanying financial statements. Certain information and footnote disclosures normally included in the Company’s annual audited consolidated financial statements and accompanying notes have been condensed in, or omitted from, these interim financial statements. Accordingly, the unaudited consolidated financial statements included herein should be read in conjunction with the audited consolidated financial statements and accompanying notes included in the Company’s annual report on Form 10-K for the year ended December 31, 2018, filed with the Securities and Exchange Commission on February 28, 2019. The results of operations presented in this quarterly report on Form 10-Q are not necessarily indicative of the results of operations that may be expected for any future periods. In the opinion of management, these unaudited consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, that are necessary for a fair statement of the results of all interim periods reported herein.
Newly-Adopted and Recent Accounting Pronouncements	Newly-Adopted Accounting Pronouncements Leases In February 2016, the Financial Accounting Standards Board ("FASB") issued guidance that requires companies to present assets and liabilities arising from leases on the consolidated balance sheet. The updated standard aims to increase transparency and comparability among organizations by requiring lessees to recognize right-of-use (“ROU”) assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. The Company adopted this standard on January 1, 2019 on a modified retrospective basis by applying the new standard to its lease portfolio as of January 1, 2019, while continuing to apply legacy guidance in the comparative periods. The Company elected to use the package of practical expedients available under the transition provisions of the guidance, which allows companies to not reassess prior conclusions related to contracts containing leases, lease classification and capitalization of initial direct costs. The Company also elected not to apply the hindsight practical expedient related to its lease transactions. Adoption of the standard required the Company to record ROU assets and lease liabilities for its operating leases related to real estate and co-location arrangements. The operating leases resulted in the recognition of ROU assets and lease liabilities of $362.2 million and $394.1 million, respectively, as of January 1, 2019. The adoption of the standard also resulted in elimination of deferred rent liabilities of $31.7 million, as of January 1, 2019, that are now recorded as a reduction of the ROU asset. The standard did not have an impact on the Company’s results of operations or cash flows. Stranded Tax Effects Resulting from U.S. Tax Cuts and Jobs Act In February 2018, the FASB issued guidance that allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the U.S. Tax Cuts and Jobs Act ("TCJA") that was enacted in 2017. This guidance was effective for the Company on January 1, 2019. The adoption of this new accounting guidance resulted in the reclassification of $0.9 million of income tax benefits resulting from the TCJA from accumulated other comprehensive loss to accumulated deficit. The adoption of this new accounting guidance did not have an impact on the Company's results of operations or cash flows. Recent Accounting Pronouncements In June 2016, the FASB issued guidance that introduces a new methodology for accounting for credit losses on financial instruments, including available-for-sale debt securities. The guidance establishes a new "expected loss model" that requires entities to estimate current expected credit losses on financial instruments by using all practical and relevant information. Any expected credit losses are to be reflected as allowances rather than reductions in the amortized cost of available-for-sale debt securities. This guidance will be effective for the Company on January 1, 2020. The Company does not expect application of this guidance to have a material impact on its consolidated financial statements. In August 2018, the FASB issued guidance that changes fair value measurement disclosure requirements. This guidance will be effective for the Company on January 1, 2020. The Company is evaluating the impact the update will have on its disclosures. In August 2018, the FASB issued guidance that addresses a customer’s accounting for implementation costs incurred in a cloud computing arrangement that is a service contract. The guidance aligns the accounting for costs incurred to implement a cloud computing arrangement that is a service arrangement with the guidance for capitalizing costs associated with developing or obtaining internal-use software. This guidance will be effective for the Company on January 1, 2020. The Company is evaluating the potential impact of adopting this new accounting guidance on its consolidated financial statements.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost, net of accumulated depreciation and amortization. Property and equipment generally includes purchases of items with a per-unit value greater than $1,000 and a useful life greater than one year. Depreciation and amortization are computed on a straight-line basis over the estimated useful lives of the assets. The Company periodically reviews the estimated useful lives of property and equipment. Changes to the estimated useful lives are recorded prospectively from the date of the change. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in income from operations.
Operating Leases	Operating Leases The Company enters into operating leases for real estate assets related to office space and co-location assets related to space or racks at co-location facilities and related equipment for its servers and other networking equipment. The Company determines if an arrangement contains a lease at the inception of a contract by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration and the right to obtain the economic benefits from the use of the identified asset. Upon commencement of a lease, the Company records an ROU asset that represents the Company’s right to use the underlying asset for the lease term and a lease liability that represents an obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. Lease payments are discounted at the lease commencement date using the rate implicit in the lease unless that rate is not readily determinable. As most of the Company’s leases do not provide an implicit rate, an incremental borrowing rate has been applied based on the Company's credit-adjusted risk-free rate. The incremental borrowing rate at January 1, 2019 (the date the new lease standard was adopted) was used to calculate the present value of the Company’s lease portfolio as of that date. The Company often enters into contracts that contain both lease and non-lease components. Real estate non-lease components include real estate taxes, insurance, maintenance, parking and other operating costs. Co-location non-lease components include utilities and other operating costs. As of January 1, 2019, the Company includes both lease and non-lease components of fixed costs in its lease arrangements as a single lease component. Variable costs, such as utilities based on actual usage, are not included in the measurement of ROU assets and lease liabilities but are expensed when the event determining the amount of variable consideration to be paid occurs. The Company’s lease terms often include renewal options and, particularly in the case of co-location arrangements, may include evergreen provisions. The Company’s ROU assets and lease liabilities generally do not include the options to extend, or terminate, unless it is reasonably certain that the Company will exercise these options. The Company has elected to exclude leases for certain networking equipment with terms of 12 months or less from its ROU assets and lease liabilities on its consolidated balance sheet. Lease expense is recognized on a straight-line basis over the lease term.
Equity Method Investments	Equity Method Investments The Company accounts for equity investments in which it has significant influence, but not a controlling financial interest, using the equity method of accounting. Under the equity method of accounting, investments are initially recorded at cost, less impairment, and subsequently adjusted to recognize the Company’s share of earnings or losses.

Significant Accounting Policies Update (Policies)

9 Months Ended

Sep. 30, 2019

The accompanying interim consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information. These financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in the accompanying financial statements.

Certain information and footnote disclosures normally included in the Company’s annual audited consolidated financial statements and accompanying notes have been condensed in, or omitted from, these interim financial statements. Accordingly, the unaudited consolidated financial statements included herein should be read in conjunction with the audited consolidated financial statements and accompanying notes included in the Company’s annual report on Form 10-K for the year ended December 31, 2018, filed with the Securities and Exchange Commission on February 28, 2019.

The results of operations presented in this quarterly report on Form 10-Q are not necessarily indicative of the results of operations that may be expected for any future periods. In the opinion of management, these unaudited consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, that are necessary for a fair statement of the results of all interim periods reported herein.

Newly-Adopted and Recent Accounting Pronouncements

Newly-Adopted Accounting Pronouncements

Leases

In February 2016, the Financial Accounting Standards Board ("FASB") issued guidance that requires companies to present assets and liabilities arising from leases on the consolidated balance sheet. The updated standard aims to increase transparency and comparability among organizations by requiring lessees to recognize right-of-use (“ROU”) assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. The Company adopted this standard on January 1, 2019 on a modified retrospective basis by applying the new standard to its lease portfolio as of January 1, 2019, while continuing to apply legacy guidance in the comparative periods.

The Company elected to use the package of practical expedients available under the transition provisions of the guidance, which allows companies to not reassess prior conclusions related to contracts containing leases, lease classification and capitalization of initial direct costs. The Company also elected not to apply the hindsight practical expedient related to its lease transactions.

Adoption of the standard required the Company to record ROU assets and lease liabilities for its operating leases related to real estate and co-location arrangements. The operating leases resulted in the recognition of ROU assets and lease liabilities of $362.2 million and $394.1 million, respectively, as of January 1, 2019. The adoption of the standard also resulted in elimination of deferred rent liabilities of $31.7 million, as of January 1, 2019, that are now recorded as a reduction of the ROU asset. The standard did not have an impact on the Company’s results of operations or cash flows.

Stranded Tax Effects Resulting from U.S. Tax Cuts and Jobs Act

In February 2018, the FASB issued guidance that allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the U.S. Tax Cuts and Jobs Act ("TCJA") that was enacted in 2017. This guidance was effective for the Company on January 1, 2019. The adoption of this new accounting guidance resulted in the reclassification of $0.9 million of income tax benefits resulting from the TCJA from accumulated other comprehensive loss to accumulated deficit. The adoption of this new accounting guidance did not have an impact on the Company's results of operations or cash flows.

Recent Accounting Pronouncements

In June 2016, the FASB issued guidance that introduces a new methodology for accounting for credit losses on financial instruments, including available-for-sale debt securities. The guidance establishes a new "expected loss model" that requires entities to estimate current expected credit losses on financial instruments by using all practical and relevant information. Any expected credit losses are to be reflected as allowances rather than reductions in the amortized cost of available-for-sale debt securities. This guidance will be effective for the Company on January 1, 2020. The Company does not expect application of this guidance to have a material impact on its consolidated financial statements.

In August 2018, the FASB issued guidance that changes fair value measurement disclosure requirements. This guidance will be effective for the Company on January 1, 2020. The Company is evaluating the impact the update will have on its disclosures.

In August 2018, the FASB issued guidance that addresses a customer’s accounting for implementation costs incurred in a cloud computing arrangement that is a service contract. The guidance aligns the accounting for costs incurred to implement a cloud computing arrangement that is a service arrangement with the guidance for capitalizing costs associated with developing or obtaining internal-use software. This guidance will be effective for the Company on January 1, 2020. The Company is evaluating the potential impact of adopting this new accounting guidance on its consolidated financial statements.

Property and Equipment

Property and equipment are recorded at cost, net of accumulated depreciation and amortization. Property and equipment generally includes purchases of items with a per-unit value greater than $1,000 and a useful life greater than one year. Depreciation and amortization are computed on a straight-line basis over the estimated useful lives of the assets. The Company periodically reviews the estimated useful lives of property and equipment. Changes to the estimated useful lives are recorded prospectively from the date of the change. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in income from operations.

Operating Leases

The Company enters into operating leases for real estate assets related to office space and co-location assets related to space or racks at co-location facilities and related equipment for its servers and other networking equipment. The Company determines if an arrangement contains a lease at the inception of a contract by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration and the right to obtain the economic benefits from the use of the identified asset.

Upon commencement of a lease, the Company records an ROU asset that represents the Company’s right to use the underlying asset for the lease term and a lease liability that represents an obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. Lease payments are discounted at the lease commencement date using the rate implicit in the lease unless that rate is not readily determinable. As most of the Company’s leases do not provide an implicit rate, an incremental borrowing rate has been applied based on the Company's credit-adjusted risk-free rate. The incremental borrowing rate at January 1, 2019 (the date the new lease standard was adopted) was used to calculate the present value of the Company’s lease portfolio as of that date.

The Company often enters into contracts that contain both lease and non-lease components. Real estate non-lease components include real estate taxes, insurance, maintenance, parking and other operating costs. Co-location non-lease components include utilities and other operating costs. As of January 1, 2019, the Company includes both lease and non-lease components of fixed costs in its lease arrangements as a single lease component. Variable costs, such as utilities based on actual usage, are not included in the measurement of ROU assets and lease liabilities but are expensed when the event determining the amount of variable consideration to be paid occurs.

The Company’s lease terms often include renewal options and, particularly in the case of co-location arrangements, may include evergreen provisions. The Company’s ROU assets and lease liabilities generally do not include the options to extend, or terminate, unless it is reasonably certain that the Company will exercise these options. The Company has elected to exclude leases for certain networking equipment with terms of 12 months or less from its ROU assets and lease liabilities on its consolidated balance sheet.

Lease expense is recognized on a straight-line basis over the lease term.

Equity Method Investments

The Company accounts for equity investments in which it has significant influence, but not a controlling financial interest, using the equity method of accounting. Under the equity method of accounting, investments are initially recorded at cost, less impairment, and subsequently adjusted to recognize the Company’s share of earnings or losses.