cm:Concept: us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpenseMethodologiesAndAssumptions
| Liability for Claims and Claims Adjustment Expense, Methodologies and Assumptions |
| us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpenseMethodologiesAndAssumptions |
| Methodology and assumptions for amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before a particular date (ordinarily, the balance sheet date) and the amount needed to provide for the estimated ultimate cost required to investigate and settle claims relating to insured events that have occurred on or before a particular date (ordinarily, the balance sheet date), whether or not reported to the insurer at that date. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpenseMethodologiesAndAssumptions |