|**Valuation And Qualifying Accounts**                                 | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
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|**SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Valuation And Qualifying Accounts                                     | Schedule VCincinnati Financial Corporation and SubsidiariesValuation and Qualifying Accounts(Dollars in millions)At December 31,202320222021Allowance for credit losses (1):Beginning balance, January 1$17$16$22Additions charged to costs and expenses331514Deductions(14)(14)(20)Ending balance, December 31$36$17$16Deferred tax valuation allowance:Beginning balance, January 1$31$53$56Additions charged to costs and expenses———Deductions(31)(22)(3)Ending balance, December 31—3153Total valuation and qualifying accounts$36$48$69Notes to Schedule V:(1) Includes allowances for credit losses related to premiums receivable, reinsurance recoverable, finance receivablesandfixed-maturity securities.
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|Cincinnati Financial Corporation and Subsidiaries                    
|Valuation and Qualifying Accounts                                    
|(Dollars in millions)                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Allowance for credit losses (1):                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Beginning balance, January 1                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
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|Additions charged to costs and expenses                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Deductions                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Ending balance, December 31                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Deferred tax valuation allowance:                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Beginning balance, January 1                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Additions charged to costs and expenses                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Deductions                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Ending balance, December 31                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Total valuation and qualifying accounts                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
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X- DefinitionThe entire disclosure for valuation and qualifying accounts and reserves.
+ ReferencesReference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-X (SX) -Number 210 -Section 12 -Subsection 09 -Publisher SECReference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-4
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