| **Cover Page Cover Page**                   | Dec. 11, 2020             |
|---------------------------------------------|---------------------------|
| **Cover [Abstract]**                        |                      |
| Document Type                               | 8-K                       |
| Document Period End Date                    | Dec. 11,  2020            |
| 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                     |

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The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented.  If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.
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The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.
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Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.
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The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.
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Local phone number for entity.
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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.
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