cm:Table: us-gaap:CausesOfIncreaseDecreaseInLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseTable
| Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Table] |
| us-gaap:CausesOfIncreaseDecreaseInLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseTable |
| Description of the reasons for the change in incurred claims and claim adjustment expenses recognized in the income statement attributable to insured events of prior fiscal years. Also includes disclosures of additional premiums or return premiums accrued as a result of changes in incurred claims and claim adjustment expenses. |
| cm:Table |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:CausesOfIncreaseDecreaseInLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseTable |