The number of operating partnetship units of CyrusOne LP sold during the period.

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The amount of borrowings outstanding on the accounts receivable securitization facility as of the balance sheet date.

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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

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Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

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Debt Debt - Schedule of Debt (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended			6 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Debt Instrument [Line Items]
Equity Method Investment Sold, Partnership Units	6.0	14.3	16.0
Current portion of long-term debt		$ 12.5		$ 12.5		$ 11.6
Corporate Credit Agreement		0.0		0.0
Receivables facility amount outstanding		2.6		2.6		19.2
Long-term debt, less current portion		1,379.0		1,379.0		1,689.4
Net unamortized discount		(1.6)		(1.6)		(3.2)
Total debt		1,391.5		1,391.5		1,701.0
Loss on extinguishment of debt		$ (13.5)	$ 0.0	$ (13.5)	$ 0.0
Senior Notes due 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage
Senior Subordinated Notes due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.75%		8.75%
Debt Instrument, Face Amount		$ 0.0		$ 0.0		300.0
Capital lease Obligations and Other Debt [Member]
Debt Instrument [Line Items]
Current portion of long-term debt		7.1		7.1		6.2
Long-term debt, less current portion		$ 62.2		$ 62.2		9.9
Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.375%		8.375%
Debt Instrument, Face Amount		$ 616.1		$ 616.1		661.2
Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		7.25%		7.25%
Debt Instrument, Face Amount		$ 40.0		$ 40.0		40.0
Various Cincinnati Bell Telephone Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		134.5		134.5		134.5
Long-term debt, less current portion, before deducting unamortized discount or premium [Member]
Debt Instrument [Line Items]
Long-term debt, less current portion		1,380.6		1,380.6		1,692.6
Current Portion of Long-Term Debt [Member] \| Tranche B Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		5.4		5.4		5.4
Long-Term Debt, Less Current Portion [Member] \| Tranche B Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		525.2		525.2		$ 527.8
Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 107.9	$ 45.1		45.1
Debt Instrument, Redemption Price, Percentage	105.30%	106.45%
Loss on extinguishment of debt	$ 6.0	$ 3.1
Senior Subordinated Notes due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 300.0		$ 300.0
Debt Instrument, Redemption Price, Percentage		102.188%
Loss on extinguishment of debt		$ 10.4