| Standard label: | SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Net Investment Income |
| Name: | us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersNetInvestmentIncome |
| Documentation: | Amount of net investment income earned by property-casualty insurance underwriter. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersNetInvestmentIncome |
| Label | Role | Language |
| SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Net Investment Income | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 944 235 S99 3 (SX 210.12-18(Column G)) | http://www.xbrl.org/2003/role/disclosureRef | 944 |