| Standard label: | Insurance Disclosure [Text Block] |
| Name: | us-gaap:InsuranceDisclosureTextBlock |
| Documentation: | The entire disclosure for the types of coverages and products sold, and the assets, obligations, recorded liabilities, revenues and expenses arising therefrom, and the amounts of and methodologies and assumptions used in determining the amounts of such items. |
| Object type: | cm:Level1TextBlock |
| 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:InsuranceDisclosureTextBlock |
| Label | Role | Language |
| Insurance Disclosure [Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 944 | http://fasb.org/us-gaap/role/ref/legacyRef | 944 |