| Standard label: | Net Investment Income |
| Name: | us-gaap:NetInvestmentIncome |
| Documentation: | Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments. |
| 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:NetInvestmentIncome |
| Label | Role | Language |
| Net Investment Income | http://www.xbrl.org/2003/role/label | en-US |
| Net Investment Income, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 944 220 S99 1 (SX 210.7-04(2)) | http://www.xbrl.org/2003/role/disclosureRef | 944 |
| Part Of Roll Up: |
| us-gaap:Revenues |