Formation	6 Months Ended
Formation	Jun. 30, 2015
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. 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 ("Predecessor") in exchange for the issuance of 123.7 million 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 underwriting 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%. On June 25, 2014, CyrusOne Inc. completed a public offering of approximately 16.0 million shares of its common stock, including 2.1 million shares of common stock issued upon the exercise in full by the underwriters of their option to purchase additional shares, at a price to the public of $23.25 per share, or $371.7 million. CyrusOne Inc. used the proceeds of $355.9 million, net of underwriting discounts of $15.8 million, to acquire 16.0 million common units of limited partnership interests in the operating partnership from a subsidiary of CBI. On April 7, 2015, CyrusOne Inc. completed a public offering of approximately 14.3 million shares of its common stock, including approximately 1.9 million shares of common stock issued upon the exercise in full by the underwriters of their option to purchase additional shares, at a price to the public of $31.12 per share, or $443.8 million. CyrusOne Inc. used the proceeds of $426.0 million, net of underwriting costs of $17.8 million, to acquire approximately 14.3 million common units of limited partnership interests in the operating partnership from two subsidiaries of CBI. On April 28, 2015, CyrusOne LP entered into an Agreement and Plan of Merger (the “Merger Agreement”) that provided for the acquisition of four data center facilities and two work area recovery facilities serving the New York metropolitan area through the acquisition of Cervalis Holdings LLC ("Cervalis") for approximately $400 million, excluding transaction related expenses. Simultaneously, CyrusOne Inc. obtained financing commitments from KeyBank to provide an unsecured $300 million bridge loan facility. Such commitments were terminated when the Company amended its Credit Agreement on June 22, 2015. See Note 6 below. The transaction closed on July 1, 2015. See Note 15 below. On June 26, 2015, CyrusOne Inc. completed a public offering of approximately 13.0 million shares of its common stock, including 1.7 million shares of common stock issued upon the exercise in full by the underwriters of their option to purchase additional shares, at a price to the public of $30.00 per share, or $389.9 million. CyrusOne Inc. used $203 million of the total proceeds of $373.3 million, net of underwriting costs of $16.6 million, to finance the acquisition of Cervalis, to pay fees and expenses related to the Cervalis acquisition and for general corporate purposes. The balance of the purchase price was funded with proceeds from CyrusOne Inc.'s offering of 6.375% senior notes due 2022 and borrowings under its amended credit facility. See Note 15 below. In addition, CyrusOne used the remaining $170.3 million of the net proceeds from the offering to acquire approximately 6.0 million common units of limited partnership interests in the operating partnership from a subsidiary of CBI. The purchase of the partnership interests was completed on July 1, 2015. As of June 30, 2015, and after giving effect to the April 2015 and June 2015 equity offerings and the use of proceeds therefrom, the total number of outstanding shares of common stock and operating partnership units was 72.6 million which reflects the purchase of the operating units on July 1. CBI held a 8.7% noncontrolling interest in the operating partnership. As of June 30, 2015, and after giving effect to the April 2015 and June 2015 equity offerings and use of proceeds therefrom, CBI owned approximately 11.3% of CyrusOne through its 2.6% interest in the outstanding shares of common stock of CyrusOne Inc. and its 8.7% interest in the common units of the limited partnership interest of CyrusOne LP that may be exchanged by CBI for common stock.

CyrusOne LP 10-Q