cm:Member: us-gaap:InsuranceContractRightsAndObligationsFairValueOptionMember
| Insurance Contract, Rights and Obligations [Member] |
| us-gaap:InsuranceContractRightsAndObligationsFairValueOptionMember |
| Rights and obligations under an insurance contract that is not a financial instrument (because it requires or permits the insurer to provide goods or services rather than a cash settlement), but whose terms permit the insurer to settle by paying a third party to provide those goods or services. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:InsuranceContractRightsAndObligationsFairValueOptionMember |