cm:Concept: us-gaap:ReinsuranceRecoverablesOnUnpaidLossesAllowance
| Reinsurance Recoverables on Unpaid Losses, Allowance |
| us-gaap:ReinsuranceRecoverablesOnUnpaidLossesAllowance |
| Amount of valuation allowance for reinsurance recoverables for losses reported to the ceding insurer but not yet paid, and for amounts expected based upon statistical projections and other measures of incurred losses and loss settlement expenses which have not yet been reported to the ceding insurer. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:ReinsuranceRecoverablesOnUnpaidLossesAllowance |