| Cover Page Cover Page | May 08, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | May 8, 2021 |
| Entity Registrant Name | CINCINNATI FINANCIAL CORP |
| Entity Incorporation, State or Country Code | OH |
| Entity File Number | 0-4604 |
| Entity Tax Identification Number | 31-0746871 |
| Entity Address, Address Line One | 6200 S. Gilmore Road |
| Entity Address, City or Town | Fairfield, |
| Entity Address, State or Province | OH |
| Entity Address, Postal Zip Code | 45014‑5141 |
| City Area Code | 513 |
| Local Phone Number | 870-2000 |
| Title of 12(b) Security | Common stock |
| Trading Symbol | CINF |
| Security Exchange Name | NASDAQ |
| 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 | 0000020286 |
| Amendment Flag | false |
