cm:Concept: us-gaap:StatutoryAccountingPracticesPermittedPracticeAmount
| Statutory Accounting Practices, Permitted Practice, Amount |
| us-gaap:StatutoryAccountingPracticesPermittedPracticeAmount |
| Amount of each item listed to reconcile the differences as of the balance sheet date resulting from applying state permitted statutory accounting practices rather than statutory accounting practices permitted by National Association of Insurance Commissioners. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:StatutoryAccountingPracticesPermittedPracticeAmount |