| **Accounting Policies**            | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    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| **Accounting Policies [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   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| Accounting Policies                | NOTE 1 — Accounting PoliciesThe 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, 2015, condensed consolidated balance sheet amounts are derived from the audited financial statements but do not include all disclosures required by GAAP. Our September 30, 2016, 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 2015 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 UpdatesASU 2014-12, Compensation-Stock Compensation: Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service PeriodIn June 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-12, Compensation-Stock Compensation: Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period. ASU 2014-12 requires that performance targets that affect vesting and that could be achieved after the requisite service period be treated as performance conditions. The effective date of ASU 2014-12 was for interim and annual reporting periods beginning after December 15, 2015. The company adopted this ASU and it did not have a material impact on our company’s financial position, cash flows or results of operations.ASU 2015-02, Consolidation-Amendments to the Consolidation AnalysisIn February 2015, the FASB issued ASU 2015-02, Consolidation-Amendments to the Consolidation Analysis. ASU 2015-02 makes amendments to the current consolidation guidance, focusing mainly on the investment management industry; however, entities across all industries may be impacted. The effective date of ASU 2015-02 was for interim and annual reporting periods beginning after December 15, 2015. The company adopted this ASU and it did not have a material impact on our company’s financial position, cash flows or results of operations.Pending Accounting UpdatesASU 2014-09 Revenue from Contracts with Customers In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. ASU 2014-09 requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. Insurance contracts do not fall within the scope of this ASU. The effective date of ASU 2014-09 is for annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted; however, it is not expected to have a material impact on our company’s financial position, cash flows or results of operations.ASU 2015-09, Financial Services-Insurance: Disclosures about Short-Duration ContractsIn May 2015, the FASB issued ASU 2015-09, Financial Services-Insurance: Disclosures About Short-Duration Contracts. ASU 2015-09 requires entities to provide additional disclosures about the liability for loss and loss expense reserves to increase the transparency of significant estimates. ASU 2015-09 also requires entities to disclose information about significant changes in methodologies and assumptions used to calculate the liability for loss and loss expense reserves, including reasons for the change and the effects on the financial statements. ASU 2015-09 also requires entities to disclose a rollforward of the liability of loss and loss expense reserves for annual and interim reporting periods. The effective date of ASU 2015-09 is for annual reporting periods beginning after December 15, 2015, and interim reporting periods beginning after December 15, 2016. The ASU has not yet been adopted and will not have a material impact on our company’s financial position, cash flows or results of operations, but the ASU will require additional disclosures to our annual and interim reporting periods.ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial LiabilitiesIn January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 revises the accounting related to the classification and measurement of investments in equity securities and the presentation of certain fair value changes for financial liabilities measured at fair value. The effective date of ASU 2016-01 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted. Management is currently evaluating the impact on our company’s consolidated financial position, cash flows and results of operations.ASU 2016-02, Leases (Topic 842)In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). The main provision of ASU 2016-02 requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. The effective date of ASU 2016-02 is for interim and annual reporting periods beginning after December 15, 2018. The ASU has not yet been adopted. Management is currently evaluating the impact on our company’s consolidated financial position, cash flows and results of operations.ASU 2016-07, Investments - Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of AccountingIn March 2016, the FASB issued ASU 2016-07, Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting. ASU 2016-07 eliminates the requirement to retroactively adjust an investment, results of operations, and retained earnings once an investment qualifies for use of the equity method.  It requires the equity method investor to add the cost of acquiring the additional interest in the investee to the current basis of the investor's previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting without retroactive adjustment. The effective date of ASU 2016-07 is for interim and annual reporting periods beginning after December 15, 2016. The ASU has not yet been adopted; however, it is not expected to have a material impact on our company's consolidated financial position, cash flows or results of operations.ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment AccountingIn March 2016, the FASB issued ASU 2016-09, Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. ASU 2016-09 simplifies and improves several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The effective date of ASU 2016-09 is for interim and annual reporting periods beginning after December 15, 2016. The ASU has not yet been adopted; however, it is not expected to have a material impact on our company's consolidated financial position, cash flows or results of operations.ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial InstrumentsIn June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. ASU 2016-13 amends previous guidance on the impairment of financial instruments by adding an impairment model that allows an entity to recognize expected credit losses as an allowance rather than impairing as they are incurred. The new guidance is intended to reduce complexity of credit impairment models and result in a more timely recognition of expected credit losses. The effective date of ASU 2016-13 is for interim and annual reporting periods beginning after December 15, 2019. The ASU has not yet been adopted; however, it is not expected to have a material impact on our company's consolidated financial position, cash flows or results of operations.ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash PaymentsIn August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. ASU 2016-15 addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The effective date of ASU 2016-15 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted; however, it is not expected to have a material impact on our company's consolidated financial position, cash flows or results of operations. |

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No definition available.
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| - Definition
The entire disclosure for all significant accounting policies of the reporting entity.
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