Recently Issued Accounting Standards	12 Months Ended
Dec. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Recently Issued Accounting Standards	Recently Issued Accounting Standards Accounting Standards Update (ASU) No. 2014-09 (ASU 2014-09), Revenue from Contracts with Customers (Topic 606) In May 2014, the Financial Accounting Standards Board (FASB) issued guidance that outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most of the existing revenue recognition guidance. This guidance requires an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and also requires certain additional disclosures which are effective for interim and annual reporting periods in fiscal years that begin after December 15, 2016. In July 2015, the FASB voted to approve a one-year deferral of the effective date to December 15, 2017 for interim and annual reporting periods beginning after that date and permitted early adoption of the standard, but not before the original effective date of December 15, 2016. This guidance permits two implementation approaches. Companies can chose to apply the standard retrospectively to each prior reporting period presented (full retrospective application) or retrospectively with the cumulative effect of initially applying the standard as an adjustment to the opening balance of retained earnings of the annual reporting period that includes the date of initial application (modified retrospective application). We are currently evaluating the impact of the adoption of this guidance in our consolidated financial statements. ASU No. 2014-12 (ASU 2014-12), Compensation-Stock Compensation (Topic 718): Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved After the Requisite Service Period In June 2014, the FASB issued a guidance update for the presentation of stock compensation. This guidance requires an entity to treat performance targets that can be met after the requisite service period of a share based award has ended, as a performance condition that affects vesting and is effective for interim and annual reporting periods in fiscal years that begin after December 15, 2015. Since the Company's share-based awards do not contain performance targets that could be achieved after the employee completes the requisite service, the adoption of this guidance has no impact on our consolidated financial statements. ASU No. 2014-15 (ASU 2014-15), Presentation of Financial Statements - Going Concern (Subtopic 205-40) In August 2014, the FASB issued guidance on determining when and how reporting entities must disclose going-concern uncertainties in their financial statements. The new standard requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements. This guidance is effective for annual periods ending after December 15, 2016, and interim periods thereafter; early adoption is permitted. We are currently evaluating the full impact of the new standard. ASU No. 2015-01 (ASU 2015-01), Extraordinary and Unusual Items (Subtopic 225-20): Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items In January 2015, the FASB issued guidance eliminating from U.S. GAAP the concept of an extraordinary item. An entity is no longer required to (1) segregate an extraordinary item from the results of ordinary operations; (2) separately present an extraordinary item on its income statement, net of tax, after income from continuing operations; and (3) disclose income taxes and earnings-per-share data applicable to an extraordinary item. This guidance does not affect the reporting and disclosure requirements for an event that is unusual in nature or that occurs infrequently. ASU No. 2015-02 (ASU 2015-02), Consolidation (Topic 810) In February 2015, the FASB issued guidance which amended the consolidation requirements in ASC 810 and significantly changed the consolidation analysis required under U.S. GAAP. The amendments include (1) limited partnerships will be variable interest entities; (2) changes the effect that fees paid to a decision maker or service provider have on the consolidation analysis; (3) amends how variable interests held by a reporting entity's related parties or de facto agents affect its consolidation conclusion; (4) clarifies how to determine whether the equity holders have power over the entity, and (5) the deferral of ASU 2009-17 for investments in certain investment funds has been eliminated. This guidance is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2015. The adoption of this guidance will have no impact on our consolidated financial statements as the provisions of this standard do not currently apply to CyrusOne Inc. ASU No. 2015-03 (ASU 2015-03), Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs In April 2015, the FASB issued guidance to simplify the presentation of debt issuance costs. The amendments would require that debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of debt liability, consistent with debt discounts or premiums. The recognition and measurement guidance for debt issuance costs would not be affected by this guidance. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted. The Company adopted this standard and debt issuance costs for all periods presented have been shown as a reduction from the carrying amount of the debt. ASU No. 2015-15 (ASU 2015-15), Imputation of Interest (Subtopic 835-30): Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements In August 2015, the FASB issued ASU 2015-15 to clarify the SEC staff's position on presenting and measuring debt issuance costs incurred in connection with line-of-credit arrangements given the lack of guidance on this topic in ASU 2015-03. The SEC staff has announced that it would not object to an entity deferring issuance costs ratably over the term of the line-of-credit arrangement. The Company ratably expenses the debt issuance costs over the term of its revolving line of credit and reflects any unamortized amount as a reduction from the carrying amount of its debt. ASU No. 2015-16 (ASU 2015-16), Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments In September 2015, the FASB issued ASU 2015-16 to simplify the accounting for measurement-period adjustments. Under the ASU, an acquirer must recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The ASU also requires acquirers to present separately on the face on the income statement, or disclose in the notes, the portion of the amount recorded in the current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the provisional amounts had been recognized as of the acquisition date. This guidance is effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. The adoption of this standard is not expected to have a material impact on our consolidated financial statements. ASU No. 2015-17 (ASU 2015-17), Income Taxes (Topic 740) In November 2015, the FASB issued guidance which amended the balance sheet classification requirements for deferred Taxes. The ASU requires an entity to classify all deferred tax liabilities and assets as noncurrent in the balance sheet. This guidance is effective for financial statements issued for annual periods beginning after December 15, 2016, including interim periods within those fiscal years. We are currently evaluating the full impact of the new standard. ASU No. 2016-01 (ASU 2016-01), Financial instruments-Overall (Subtopic 825-10) In January 2016, the FASB amended its standards related to the accounting of certain financial instruments. This amendment addresses certain aspects of recognition, measurement, presentation and disclosure. The new rules will become effective for annual and interim periods beginning after December 15, 2017. Early adoption is not permitted. We are in the process of evaluating the impact the amendment will have on the consolidated financial statements. ASU No. 2016-02 (ASU 2016-02), Leases (Topic 842) In February 2016, the FASB issued accounting standard update (“ASU”) No. 2016-02, Leases (Topic 842). This new lease guidance requires that an entity should recognize assets and liabilities for leases with a maximum possible term of more than 12 months. A lessee would recognize a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the leased asset (the underlying asset) for the lease term. Leases would be classified as either Type A leases (generally today’s capital leases) or Type B leases (generally today’s operating leases). For certain leases of assets other than property (for example, equipment, aircraft, cars, trucks), a lessee would classify the lease as a Type A lease and would do the following: (1) recognize a right-of-use asset and a lease liability, initially measured at the present value of lease payments and (2) recognize the unwinding of the discount on the lease liability as interest separately from the amortization of the right-of-use asset. For certain leases of property (that is, land and/or a building or part of a building), a lessee would classify the lease as a Type B lease and would do the following: (1) recognize a right-of-use asset and a lease liability, initially measured at the present value of lease payments and (2) recognize a single lease cost, combining the unwinding of the discount on the lease liability with the amortization of the right-of-use asset, on a straight-line basis. This guidance also provides accounting updates with respect to lessor accounting under a lease arrangement. This new lease guidance is effective for CyrusOne beginning in the first quarter of fiscal 2019. Entities have the option of using either a full retrospective or a modified approach (cumulative effect adjustment in period of adoption) to adopt the new guidance. Early adoption is permitted for all entities. We are currently evaluating the impact of the adoption of this guidance in our consolidated financial statements.”

Recently Issued Accounting Standards

Accounting Standards Update (ASU) No. 2014-09 (ASU 2014-09), Revenue from Contracts with Customers (Topic 606)

In May 2014, the Financial Accounting Standards Board (FASB) issued guidance that outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most of the existing revenue recognition guidance. This guidance requires an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and also requires certain additional disclosures which are effective for interim and annual reporting periods in fiscal years that begin after December 15, 2016. In July 2015, the FASB voted to approve a one-year deferral of the effective date to December 15, 2017 for interim and annual reporting periods beginning after that date and permitted early adoption of the standard, but not before the original effective date of December 15, 2016. This guidance permits two implementation approaches. Companies can chose to apply the standard retrospectively to each prior reporting period presented (full retrospective application) or retrospectively with the cumulative effect of initially applying the standard as an adjustment to the opening balance of retained earnings of the annual reporting period that includes the date of initial application (modified retrospective application). We are currently evaluating the impact of the adoption of this guidance in our consolidated financial statements.

ASU No. 2014-12 (ASU 2014-12), Compensation-Stock Compensation (Topic 718): Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved After the Requisite Service Period

In June 2014, the FASB issued a guidance update for the presentation of stock compensation. This guidance requires an entity to treat performance targets that can be met after the requisite service period of a share based award has ended, as a performance condition that affects vesting and is effective for interim and annual reporting periods in fiscal years that begin after December 15, 2015. Since the Company's share-based awards do not contain performance targets that could be achieved after the employee completes the requisite service, the adoption of this guidance has no impact on our consolidated financial statements.

ASU No. 2014-15 (ASU 2014-15), Presentation of Financial Statements - Going Concern (Subtopic 205-40)

In August 2014, the FASB issued guidance on determining when and how reporting entities must disclose going-concern uncertainties in their financial statements. The new standard requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements. This guidance is effective for annual periods ending after December 15, 2016, and interim periods thereafter; early adoption is permitted. We are currently evaluating the full impact of the new standard.

ASU No. 2015-01 (ASU 2015-01), Extraordinary and Unusual Items (Subtopic 225-20): Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items

In January 2015, the FASB issued guidance eliminating from U.S. GAAP the concept of an extraordinary item. An entity is no longer required to (1) segregate an extraordinary item from the results of ordinary operations; (2) separately present an extraordinary item on its income statement, net of tax, after income from continuing operations; and (3) disclose income taxes and earnings-per-share data applicable to an extraordinary item. This guidance does not affect the reporting and disclosure requirements for an event that is unusual in nature or that occurs infrequently.

ASU No. 2015-02 (ASU 2015-02), Consolidation (Topic 810)

In February 2015, the FASB issued guidance which amended the consolidation requirements in ASC 810 and significantly changed the consolidation analysis required under U.S. GAAP. The amendments include (1) limited partnerships will be variable interest entities; (2) changes the effect that fees paid to a decision maker or service provider have on the consolidation analysis; (3) amends how variable interests held by a reporting entity's related parties or de facto agents affect its consolidation conclusion; (4) clarifies how to determine whether the equity holders have power over the entity, and (5) the deferral of ASU 2009-17 for investments in certain investment funds has been eliminated. This guidance is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2015. The adoption of this guidance will have no impact on our consolidated financial statements as the provisions of this standard do not currently apply to CyrusOne Inc.

ASU No. 2015-03 (ASU 2015-03), Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs

In April 2015, the FASB issued guidance to simplify the presentation of debt issuance costs. The amendments would require that debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of debt liability, consistent with debt discounts or premiums. The recognition and measurement guidance for debt issuance costs would not be affected by this guidance. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted. The Company adopted this standard and debt issuance costs for all periods presented have been shown as a reduction from the carrying amount of the debt.

ASU No. 2015-15 (ASU 2015-15), Imputation of Interest (Subtopic 835-30): Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements

In August 2015, the FASB issued ASU 2015-15 to clarify the SEC staff's position on presenting and measuring debt issuance costs incurred in connection with line-of-credit arrangements given the lack of guidance on this topic in ASU 2015-03. The SEC staff has announced that it would not object to an entity deferring issuance costs ratably over the term of the line-of-credit arrangement. The Company ratably expenses the debt issuance costs over the term of its revolving line of credit and reflects any unamortized amount as a reduction from the carrying amount of its debt.

ASU No. 2015-16 (ASU 2015-16), Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments

In September 2015, the FASB issued ASU 2015-16 to simplify the accounting for measurement-period adjustments. Under the ASU, an acquirer must recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The ASU also requires acquirers to present separately on the face on the income statement, or disclose in the notes, the portion of the amount recorded in the current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the provisional amounts had been recognized as of the acquisition date. This guidance is effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. The adoption of this standard is not expected to have a material impact on our consolidated financial statements.

ASU No. 2015-17 (ASU 2015-17), Income Taxes (Topic 740)

In November 2015, the FASB issued guidance which amended the balance sheet classification requirements for deferred Taxes. The ASU requires an entity to classify all deferred tax liabilities and assets as noncurrent in the balance sheet. This guidance is effective for financial statements issued for annual periods beginning after December 15, 2016, including interim periods within those fiscal years. We are currently evaluating the full impact of the new standard.

ASU No. 2016-01 (ASU 2016-01), Financial instruments-Overall (Subtopic 825-10)

In January 2016, the FASB amended its standards related to the accounting of certain financial instruments. This amendment addresses certain aspects of recognition, measurement, presentation and disclosure. The new rules will become effective for annual and interim periods beginning after December 15, 2017. Early adoption is not permitted. We are in the process of evaluating the impact the amendment will have on the consolidated financial statements.

ASU No. 2016-02 (ASU 2016-02), Leases (Topic 842)

In February 2016, the FASB issued accounting standard update (“ASU”) No. 2016-02, Leases (Topic 842). This new lease guidance requires that an entity should recognize assets and liabilities for leases with a maximum possible term of more than 12 months. A lessee would recognize a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the leased asset (the underlying asset) for the lease term. Leases would be classified as either Type A leases (generally today’s capital leases) or Type B leases (generally today’s operating leases). For certain leases of assets other than property (for example, equipment, aircraft, cars, trucks), a lessee would classify the lease as a Type A lease and would do the following: (1) recognize a right-of-use asset and a lease liability, initially measured at the present value of lease payments and (2) recognize the unwinding of the discount on the lease liability as interest separately from the amortization of the right-of-use asset. For certain leases of property (that is, land and/or a building or part of a building), a lessee would classify the lease as a Type B lease and would do the following: (1) recognize a right-of-use asset and a lease liability, initially measured at the present value of lease payments and (2) recognize a single lease cost, combining the unwinding of the discount on the lease liability with the amortization of the right-of-use asset, on a straight-line basis. This guidance also provides accounting updates with respect to lessor accounting under a lease arrangement. This new lease guidance is effective for CyrusOne beginning in the first quarter of fiscal 2019. Entities have the option of using either a full retrospective or a modified approach (cumulative effect adjustment in period of adoption) to adopt the new guidance. Early adoption is permitted for all entities. We are currently evaluating the impact of the adoption of this guidance in our consolidated financial statements.”