| Standard label: | Policyholders' Dividend [Policy Text Block] |
| Name: | us-gaap:PolicyholdersDividendPolicy |
| Documentation: | Disclosure of accounting policy for method of allocating earnings and dividends to policyholder. Includes, but is not limited to, policyholder in participating insurance contract. |
| Object type: | cm:Level2TextBlock |
| Data type: | Text Block (HTML) (nonnum:textBlockItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:PolicyholdersDividendPolicy |
| Label | Role | Language |
| Policyholders' Dividend [Policy Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 944 20 50 2 | http://www.xbrl.org/2003/role/disclosureRef | 944 |
| FASB Accounting Standards Codification 944 210 S99 1 (SX 210.7-03(14)(b)(2)) | http://www.xbrl.org/2003/role/disclosureRef | 944 |
| FASB Accounting Standards Codification 944 50 50 1 (b) | http://www.xbrl.org/2003/role/disclosureRef | 944 |