cm:Concept: us-gaap:LifeSettlementContractsFairValueMethodFaceValueMaturingInRollingYearFour
| Life Settlement Contracts, Fair Value Method, Face Value, Maturing in Rolling Year Four |
| us-gaap:LifeSettlementContractsFairValueMethodFaceValueMaturingInRollingYearFour |
| Face value of the life insurance policies underlying the life settlement contracts accounted for under the fair value method maturing in the fourth 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 |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:LifeSettlementContractsFairValueMethodFaceValueMaturingInRollingYearFour |