cm:Concept: us-gaap:LifeSettlementContractsFairValueMethodNumberOfContractsMaturingInNextRollingTwelveMonths
| Life Settlement Contracts, Fair Value Method, Number of Contracts, Maturing in Next Rolling Twelve Months |
| us-gaap:LifeSettlementContractsFairValueMethodNumberOfContractsMaturingInNextRollingTwelveMonths |
| Number of life settlement contracts accounted for under the fair value method maturing in the next 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:LifeSettlementContractsFairValueMethodNumberOfContractsMaturingInNextRollingTwelveMonths |