cm:Concept: us-gaap:DeferredPolicyAcquisitionCostAndPresentValueOfFutureInsuranceProfitMajorCustomerExtensibleList
| Deferred Policy Acquisition Cost and Present Value of Future Insurance Profit, Customer [Extensible List] |
| us-gaap:DeferredPolicyAcquisitionCostAndPresentValueOfFutureInsuranceProfitMajorCustomerExtensibleList |
| Indicates customer for deferred policy acquisition cost and present value of future insurance profit. |
| cm:Concept |
| srt-types:extensibleListItemType |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:DeferredPolicyAcquisitionCostAndPresentValueOfFutureInsuranceProfitMajorCustomerExtensibleList |