Name:	cbb_ChangeInAccountingEstimateEffectOfChangeOnBasicAndDilutedEarningsPerShare
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The increase in depreciation expense associated with a reduction in the useful lives of property, plant and equipment.

No definition available.

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Data Type:	xbrli:monetaryItemType
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The increase in depreciation expense associated with a reduction in the useful lives of property, plant and equipment, net of tax.

No definition available.

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Namespace Prefix:	cbb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Data Type:	xbrli:stringItemType
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Period Type:	duration

The number of partnership units of CyrusOne LP, the operating partnership, owned by the Company. These partnership units are exchangeable into shares of common stock of CyrusOne Inc. on a one-for-one basis.

No definition available.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The Company's ownership interest, in shares, in the common stock of CyrusOne Inc., the publicly-traded real estate investment trust entity, following the completion of the initial public offering on January 24, 2013.

No definition available.

Name:	cbb_InvestmentownedinEquityMethodInvesteeBalanceShares
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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The Company's total combined direct and indirect owership interests in CyrusOne Inc., the REIT entity, and CyrusOne LP, the operating partnership.

No definition available.

Name:	cbb_TotalownershipinterestsinEquityMethodInvesteePercentage
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Cash dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporations that are returns of capital. Excludes dividends or distributions from equity method investments classified as operating activities.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The amount of the change in the period in the valuation allowance for a specified deferred tax asset.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 45

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=21917399&loc=d3e32123-109318