Formation	12 Months Ended
Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Formation	Formation Prior to November 20, 2012, CyrusOne was not an operative legal entity or a combination of legal entities. The accompanying combined financial statements of CyrusOne for such periods represent the data center assets and operations owned by Cincinnati Bell, Inc. (“CBI”) and, unless the context otherwise requires, its consolidated subsidiaries which historically have been maintained in various legal entities, some of which had significant unrelated business activities. The accompanying financial statements for such periods have been “carved out” of CBI’s consolidated financial statements and reflect significant assumptions and allocations. The combined financial statements do not fully reflect what the financial position, results of operations and cash flows would have been had these operations been a stand-alone company during the periods presented. As a result, historical financial information is not necessarily indicative of CyrusOne’s future results of operations, financial position and cash flows. On November 20, 2012, the Operating Partnership received a contribution of interests in real estate properties and the assumption of debt and other specified liabilities from CBI in exchange for the issuance of 123,688,687 operating partnership units to CBI. On January 24, 2013, CyrusOne Inc. completed its initial public offering (“IPO”) of common stock, issuing approximately 19.0 million shares for $337.1 million, net of underwriters' discounts. At that time the Operating Partnership executed a 2.8 to 1.0 reverse unit split, resulting in CBI owning 44.1 million Operating Partnership units. In addition, CBI exchanged approximately 1.5 million of its Operating Partnership units for 1.5 million shares of CyrusOne Inc. common stock, and CBI was issued 0.4 million shares of CyrusOne Inc. common stock in repayment for transaction costs paid by CBI. CyrusOne Inc. also issued approximately 1.1 million shares of restricted stock to its directors and employees. In addition, on January 24, 2013, CyrusOne Inc., together with CyrusOne GP, purchased approximately 21.9 million or 33.9% of the Operating Partnership’s units for $337.1 million and,through CyrusOne GP, assumed the controlling interest in the Operating Partnership. CBI retained a noncontrolling interest in the Operating Partnership of 66.1%. As of December 31, 2013, the total number of outstanding partnership units was 64.6 million, and CBI holds a 65.9% ownership in the Operating Partnership.

Formation

Prior to November 20, 2012, CyrusOne was not an operative legal entity or a combination of legal entities. The accompanying combined financial statements of CyrusOne for such periods represent the data center assets and operations owned by Cincinnati Bell, Inc. (“CBI”) and, unless the context otherwise requires, its consolidated subsidiaries which historically have been maintained in various legal entities, some of which had significant unrelated business activities. The accompanying financial statements for such periods have been “carved out” of CBI’s consolidated financial statements and reflect significant assumptions and allocations. The combined financial statements do not fully reflect what the financial position, results of operations and cash flows would have been had these operations been a stand-alone company during the periods presented. As a result, historical financial information is not necessarily indicative of CyrusOne’s future results of operations, financial position and cash flows.

On November 20, 2012, the Operating Partnership received a contribution of interests in real estate properties and the assumption of debt and other specified liabilities from CBI in exchange for the issuance of 123,688,687 operating partnership units to CBI.

On January 24, 2013, CyrusOne Inc. completed its initial public offering (“IPO”) of common stock, issuing approximately 19.0 million shares for $337.1 million, net of underwriters' discounts. At that time the Operating Partnership executed a 2.8 to 1.0 reverse unit split, resulting in CBI owning 44.1 million Operating Partnership units. In addition, CBI exchanged approximately 1.5 million of its Operating Partnership units for 1.5 million shares of CyrusOne Inc. common stock, and CBI was issued 0.4 million shares of CyrusOne Inc. common stock in repayment for transaction costs paid by CBI. CyrusOne Inc. also issued approximately 1.1 million shares of restricted stock to its directors and employees. In addition, on January 24, 2013, CyrusOne Inc., together with CyrusOne GP, purchased approximately 21.9 million or 33.9% of the Operating Partnership’s units for $337.1 million and,through CyrusOne GP, assumed the controlling interest in the Operating Partnership. CBI retained a noncontrolling interest in the Operating Partnership of 66.1%.

As of December 31, 2013, the total number of outstanding partnership units was 64.6 million, and CBI holds a 65.9% ownership in the Operating Partnership.