| Cover Page Cover Page | Feb. 25, 2019 |
| Cover page. | |
| Document Type | 8-K/A |
| Document Period End Date | Feb. 25, 2019 |
| 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 | true |
| Amendment Description | Explanatory Note:Cincinnati Financial Corporation ("Company") is filing this Amendment to supplement the Current Report on Form 8-K dated February 28, 2019 (the “Original Filing”). The Original Filing reported the closing of the transaction by which the Company acquired from Münchener Rückversicherungs Gesellschaft AG (“Munich Re”), all of the issued and outstanding share capital of MSP Underwriting Limited (MSP). The purchase price paid at closing was subject to certain post-closing adjustments. Information about the post closing adjustments and the final purchase price is set forth in Item 7.01 below. |
