| **Accounting Policies**            | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
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| **Accounting Policies [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| Accounting Policies                | ACCOUNTING POLICIES The condensed consolidated financial statements include the accounts of Cincinnati Financial Corporation and its consolidated subsidiaries, each of which is wholly owned. These statements are presented in conformity with accounting principles generally accepted in the United States of America (GAAP). All intercompany balances and transactions have been eliminated in consolidation. The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Our actual results could differ from those estimates. Our December 31, 2012, condensed consolidated balance sheet amounts are derived from the audited financial statements but do not include all disclosures required by GAAP. Our September 30, 2013, condensed consolidated financial statements are unaudited. Certain financial information that is included in annual financial statements prepared in accordance with GAAP is not required for interim reporting and has been condensed or omitted. We believe that we have made all adjustments, consisting only of normal recurring accruals, that are necessary for fair presentation. These condensed consolidated financial statements should be read in conjunction with our consolidated financial statements included in our 2012 Annual Report on Form 10-K. The results of operations for interim periods do not necessarily indicate results to be expected for the full year. Adopted Accounting Updates ASU 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income  In February 2013, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU 2013-02 requires entities to present in either a single note or parenthetically on the face of the financial statements, the effect of significant amounts reclassified from each component of accumulated other comprehensive income based on its source and the income statement line items affected by the reclassification. The company adopted this ASU during the first quarter of 2013, and it did not have a material impact on our company’s financial position, cash flows or results of operations. See Note 7, Accumulated Other Comprehensive Income, for further details. |

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| - Definition
The entire disclosure for all significant accounting policies of the reporting entity.
+ References
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