| Standard label: | Policyholder Account Balance |
| Name: | us-gaap:PolicyholderFunds |
| Documentation: | Amount due to policyholder. Includes, but is not limited to, unpaid policy dividend, retrospective refund, and undistributed earnings on participating business. Excludes future policy benefit and claim expense. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:PolicyholderFunds |
| Label | Role | Language |
| Policyholder Account Balance | http://www.xbrl.org/2003/role/label | en-US |
| Policyholder Account Balance, Ending Balance | http://www.xbrl.org/2003/role/periodEndLabel | en-US |
| Policyholder Account Balance, Beginning Balance | http://www.xbrl.org/2003/role/periodStartLabel | en-US |
| Policyholder Account Balance, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 944 40 50 7A (a) | http://www.xbrl.org/2003/role/disclosureRef | 944 |
| FASB Accounting Standards Codification 944 40 50 7A (c) | http://www.xbrl.org/2003/role/disclosureRef | 944 |
| FASB Accounting Standards Codification 944 40 55 29F | http://www.xbrl.org/2003/role/exampleRef | 944 |
| FASB Accounting Standards Codification 944 40 50 7A (d) | http://www.xbrl.org/2003/role/disclosureRef | 944 |