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