Name:	ck0000716133_LongTermDebtExcludingFinanceLeasesCurrent
Namespace Prefix:	ck0000716133_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Principal amount of long-term debt (excluding finance leases) before deducting unamortized discount or premium.

No definition available.

Name:	ck0000716133_LongTermDebtExcludingFinanceLeasesGross
Namespace Prefix:	ck0000716133_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of long-term debt (excluding finance leases) net of unamortized discount or premium.

No definition available.

Name:	ck0000716133_LongTermDebtExcludingFinanceLeasesNet
Namespace Prefix:	ck0000716133_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Principal amount of long-term debt (excluding finance leases) maturing after the fifth fiscal year following the latest fiscal year.

No definition available.

Name:	ck0000716133_LongTermDebtExcludingFinanceLeasesRepaymentsOfPrincipalAfterYearFive
Namespace Prefix:	ck0000716133_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Principal amount of long-term debt (excluding finance leases) maturing in the fifth fiscal year following the latest fiscal year.

No definition available.

Name:	ck0000716133_LongTermDebtExcludingFinanceLeasesRepaymentsOfPrincipalInYearFive
Namespace Prefix:	ck0000716133_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Principal amount of long-term debt (excluding finance leases) maturing in the fourth fiscal year following the latest fiscal year.

No definition available.

Name:	ck0000716133_LongTermDebtExcludingFinanceLeasesRepaymentsOfPrincipalInYearFour
Namespace Prefix:	ck0000716133_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Principal amount of long-term debt (excluding finance leases) maturing in the third fiscal year following the latest fiscal year.

No definition available.

Name:	ck0000716133_LongTermDebtExcludingFinanceLeasesRepaymentsOfPrincipalInYearThree
Namespace Prefix:	ck0000716133_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Principal amount of long-term debt (excluding finance leases) maturing in the second fiscal year following the latest fiscal year.

No definition available.

Name:	ck0000716133_LongTermDebtExcludingFinanceLeasesRepaymentsOfPrincipalInYearTwo
Namespace Prefix:	ck0000716133_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

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

Amount, after accumulated amortization, of debt discount (premium).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-1A

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482900/835-30-50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D

Name:	us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount, after accumulated amortization, of debt issuance costs classified as noncurrent. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.