cm:Table: us-gaap:DeferredPolicyAcquisitionCostAndPresentValueOfFutureProfitTable
| Deferred Policy Acquisition Cost and Present Value of Future Profit [Table] |
| us-gaap:DeferredPolicyAcquisitionCostAndPresentValueOfFutureProfitTable |
| Disclosure of information about deferred policy acquisition cost and present value of future profit from insurance contract acquired in business combination. |
| cm:Table |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:DeferredPolicyAcquisitionCostAndPresentValueOfFutureProfitTable |