cm:Concept: us-gaap:StatutoryAccountingPracticesStatutoryCapitalAndSurplusRequired
| Statutory Accounting Practices, Statutory Capital and Surplus Required |
| us-gaap:StatutoryAccountingPracticesStatutoryCapitalAndSurplusRequired |
| Amount of statutory capital required to be maintained as of the balance sheet date under prescribed or permitted statutory accounting practices. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:StatutoryAccountingPracticesStatutoryCapitalAndSurplusRequired |