| Standard label: | Deferred Policy Acquisition Costs [Table Text Block] | 
| Name: | us-gaap:DeferredPolicyAcquisitionCostsTableTextBlock | 
| Documentation: | Tabular disclosure of the movement in deferred policy acquisition costs. | 
| Object type: | cm:Level3TextBlock | 
| 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:DeferredPolicyAcquisitionCostsTableTextBlock | 
| Label | Role | Language | 
| Deferred Policy Acquisition Costs [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US | 
| Reference | Role | Topic | 
| FASB Accounting Standards Codification 944 30 50 2B | http://www.xbrl.org/2003/role/disclosureRef | 944 | 
| FASB Accounting Standards Codification 944 30 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 944 | 
| FASB Accounting Standards Codification 944 30 55 2 | http://www.xbrl.org/2003/role/exampleRef | 944 | 
| FASB Accounting Standards Codification 944 40 65 2 (g)(1) | http://www.xbrl.org/2003/role/disclosureRef | 944 |