cm:Concept: us-gaap:LongDurationContractsAssumptionsByProductAndGuaranteeOtherRate
| Long-Duration Contracts, Assumptions by Product and Guarantee, Other Rate |
| us-gaap:LongDurationContractsAssumptionsByProductAndGuaranteeOtherRate |
| Anticipated rate, classified as other, for assumptions included in determining the amount of the specified guaranteed benefit obligation. |
| cm:Concept |
| Percent (num:percentItemType) |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:LongDurationContractsAssumptionsByProductAndGuaranteeOtherRate |