| Document and Entity Information | Apr. 08, 2021 |
| Entity Listings [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Apr. 8, 2021 |
| Entity Registrant Name | CINCINNATI BELL INC. |
| Entity Incorporation, State or Country Code | OH |
| Entity File Number | 001-8519 |
| Entity Tax Identification Number | 31-1056105 |
| Entity Address, Address Line One | 221 East Fourth Street |
| Entity Address, City or Town | Cincinnati |
| Entity Address, State or Province | OH |
| Entity Address, Postal Zip Code | 45202 |
| City Area Code | 513 |
| Local Phone Number | 397-9900 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000716133 |
| Common Shares ($0.01 par value) [Member] | |
| Entity Listings [Line Items] | |
| Title of 12(b) Security | Common Shares ($0.01 par value) |
| Trading Symbol | CBB |
| Security Exchange Name | NYSE |
| Depositary Shares, each representing 1/20 interest in a Share of 6 3/4% Cumulative Convertible Preferred Stock, without par value [Member] | |
| Entity Listings [Line Items] | |
| Title of 12(b) Security | Depositary Shares, each representing 1/20 interest in a Share of 6 3/4% Cumulative Convertible Preferred Stock, without par value |
| Trading Symbol | CBB.PB |
| Security Exchange Name | NYSE |
