cm:Concept: us-gaap:LifeSettlementContractsFairValueMethodNumberOfContractsMaturingInRollingYearThree
| Life Settlement Contracts, Fair Value Method, Number of Contracts, Maturing in Rolling Year Three |
| us-gaap:LifeSettlementContractsFairValueMethodNumberOfContractsMaturingInRollingYearThree |
| Number of life settlement contracts accounted for under the fair value method maturing in the third rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. |
| cm:Concept |
| Integer (xbrli:integerItemType) |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:LifeSettlementContractsFairValueMethodNumberOfContractsMaturingInRollingYearThree |