cm:Concept: us-gaap:MarketRiskBenefitMeasurementInput
| Market Risk Benefit, Measurement Input |
| us-gaap:MarketRiskBenefitMeasurementInput |
| Value of measurement input used to measure contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk. |
| cm:Concept |
| Decimal (xbrli:decimalItemType) |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:MarketRiskBenefitMeasurementInput |