The total amount of restructuring and severance payments that have occurred during the current period.

No definition available.

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

- Definition

The expense recognized during the current period for restructuring and severance-related charges.

+ References

No definition available.

+ Details

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

- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of known and estimated obligations associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, which are expected to be paid in the next twelve months or in the normal operating cycle if longer. Costs of such activities include those for one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, relocating employees, and costs associated with an ongoing benefit arrangement, but excludes costs associated with the retirement of a long-lived asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b)(2))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of known and estimated costs associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, which are expected to be paid after one year or beyond the next operating cycle, if longer. Costs of such activities include those for one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, and relocating employees, and costs associated with an ongoing benefit arrangement, but excludes costs associated with the retirement of a long-lived asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

Name:	us-gaap_RestructuringReserveNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

Name:	us-gaap_RestructuringReserveRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cbb_ItServicesAndHardwareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=cbb_LeaseAbandonmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_OtherRestructuringMember
Namespace Prefix:
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Restructuring and Severance Charges (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Reserve [Roll Forward]
Beginning balance			$ 11.2		$ 11.2	$ 1.1	$ 4.9
Restructuring and severance related charges	$ 3.5	$ 3.6	25.6	$ 11.9	32.7	11.9	6.0
Utilizations					(29.4)	(1.8)	(9.8)
Ending balance	14.5			11.2	14.5	11.2	1.1
Restructuring liabilities included in other current liabilities	12.0			7.4	12.0	7.4
Restructuring liabilities included in other noncurrent liabilities	2.5			3.8	2.5	3.8
Entertainment and Communications [Member]
Restructuring Reserve [Roll Forward]
Beginning balance			7.5		7.5	0.8	3.9
Restructuring and severance related charges					27.9	7.7	1.6
Utilizations					(23.1)	(1.0)	(4.7)
Ending balance	12.3			7.5	12.3	7.5	0.8
IT Services and Hardware [Member]
Restructuring Reserve [Roll Forward]
Beginning balance			3.0		3.0	0.3	0.3
Restructuring and severance related charges					4.8	3.3	2.8
Utilizations					(5.6)	(0.6)	(2.8)
Ending balance	2.2			3.0	2.2	3.0	0.3
Corporate Segment [Member]
Restructuring Reserve [Roll Forward]
Beginning balance			0.7		0.7	0.0	0.7
Restructuring and severance related charges					0.0	0.9	1.6
Utilizations					(0.7)	(0.2)	(2.3)
Ending balance	0.0			0.7	0.0	0.7	0.0
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Beginning balance			11.0		11.0	0.2	3.0
Restructuring and severance related charges					32.7	12.5	3.3
Utilizations					(29.3)	(1.7)	(6.1)
Ending balance	14.4			11.0	14.4	11.0	0.2
Lease Abandonment [Member]
Restructuring Reserve [Roll Forward]
Beginning balance			0.2		0.2	0.8	1.8
Restructuring and severance related charges					0.0	(0.5)	0.3
Utilizations					(0.1)	(0.1)	(1.3)
Ending balance	0.1			0.2	0.1	0.2	0.8
Contract Terminations [Member]
Restructuring Reserve [Roll Forward]
Beginning balance			$ 0.0		0.0	0.1	0.1
Restructuring and severance related charges					0.0	(0.1)	2.4
Utilizations					0.0	0.0	(2.4)
Ending balance	$ 0.0			$ 0.0	$ 0.0	$ 0.0	$ 0.1