cm:Concept: us-gaap:LifeSettlementContractsInvestmentMethodCarryingAmountMaturingInRollingYearFour
| Life Settlement Contracts, Investment Method, Carrying Amount, Maturing in Rolling Year Four |
| us-gaap:LifeSettlementContractsInvestmentMethodCarryingAmountMaturingInRollingYearFour |
| Amount of life settlement contracts accounted for under the investment 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:LifeSettlementContractsInvestmentMethodCarryingAmountMaturingInRollingYearFour |