Income Taxes	3 Months Ended
Mar. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes CyrusOne Inc. will elect to be taxed as a REIT under the Code, as amended, by making our REIT election upon filing of our 2013 REIT federal income tax return. To qualify as a REIT, we are required to distribute at least 90% of our taxable income to our stockholders and meet various other requirements imposed by the Code relating to such matters as operating results, asset holdings, distribution levels and diversity of stock ownership. Provided we qualify for taxation as a REIT, we are generally not subject to corporate level federal income tax on the earnings distributed currently to our shareholders. It is our policy and intent, subject to change, to distribute 100% of our taxable income and therefore no provision is required in the accompanying financial statements for federal income taxes with regards to activities of the CyrusOne Inc. and its subsidiary pass-through entities. We have elected to designate two subsidiaries as taxable REIT subsidiaries (each a “TRS”). A TRS may perform services for our tenants that would otherwise be considered impermissible for REITs. The income generated from these services is taxed at federal and state corporate rates. Income tax expense was immaterial for the three months ended March 31, 2014 and period ended March 31, 2013. In conjunction with the Company’s tax sharing arrangement with CBI, CBI may be required to file Texas margin tax returns on a consolidated, combined or unitary basis with the Company for any given year. If such return is prepared by CBI on a combined or consolidated basis to include the Company, the related Texas margin tax of the Company will be paid by CBI. The Company will then reimburse CBI for its portion of the related Texas margin tax. The Texas margin tax payable was $1.4 million as of March 31, 2014 and December 31, 2013. For certain entities we calculate deferred tax assets and liabilities for temporary differences in the basis between financial statement and income tax assets and liabilities. Deferred income taxes are recalculated annually at rates then in effect. Valuation allowances are recorded to reduce deferred tax assets to amounts that are more likely than not to be realized. The ultimate realization of the deferred tax assets depends upon our ability to generate future taxable income during the periods in which basis differences and other deductions become deductible and prior to the expiration of the net operating loss carryforwards. Deferred tax assets (net of valuation allowance) and liabilities were accrued, as necessary, for the periods ended March 31, 2014 and December 31, 2013. As of March 31, 2014 and December 31, 2013, we had a total net deferred tax asset balance of $3.6 million that was offset by a valuation reserve of $3.6 million.

Income Taxes

3 Months Ended

Mar. 31, 2014

CyrusOne Inc. will elect to be taxed as a REIT under the Code, as amended, by making our REIT election upon filing of our 2013 REIT federal income tax return. To qualify as a REIT, we are required to distribute at least 90% of our taxable income to our stockholders and meet various other requirements imposed by the Code relating to such matters as operating results, asset holdings, distribution levels and diversity of stock ownership. Provided we qualify for taxation as a REIT, we are generally not subject to corporate level federal income tax on the earnings distributed currently to our shareholders. It is our policy and intent, subject to change, to distribute 100% of our taxable income and therefore no provision is required in the accompanying financial statements for federal income taxes with regards to activities of the CyrusOne Inc. and its subsidiary pass-through entities.

We have elected to designate two subsidiaries as taxable REIT subsidiaries (each a “TRS”). A TRS may perform services for our tenants that would otherwise be considered impermissible for REITs. The income generated from these services is taxed at federal and state corporate rates. Income tax expense was immaterial for the three months ended March 31, 2014 and period ended March 31, 2013.

In conjunction with the Company’s tax sharing arrangement with CBI, CBI may be required to file Texas margin tax returns on a consolidated, combined or unitary basis with the Company for any given year. If such return is prepared by CBI on a combined or consolidated basis to include the Company, the related Texas margin tax of the Company will be paid by CBI. The Company will then reimburse CBI for its portion of the related Texas margin tax. The Texas margin tax payable was $1.4 million as of March 31, 2014 and December 31, 2013.

For certain entities we calculate deferred tax assets and liabilities for temporary differences in the basis between financial statement and income tax assets and liabilities. Deferred income taxes are recalculated annually at rates then in effect. Valuation allowances are recorded to reduce deferred tax assets to amounts that are more likely than not to be realized. The ultimate realization of the deferred tax assets depends upon our ability to generate future taxable income during the periods in which basis differences and other deductions become deductible and prior to the expiration of the net operating loss carryforwards. Deferred tax assets (net of valuation allowance) and liabilities were accrued, as necessary, for the periods ended March 31, 2014 and December 31, 2013. As of March 31, 2014 and December 31, 2013, we had a total net deferred tax asset balance of $3.6 million that was offset by a valuation reserve of $3.6 million.