cm:Concept: us-gaap:LongDurationContractsHedgingStrategies
| Long-Duration Contracts, Hedging Strategies |
| us-gaap:LongDurationContractsHedgingStrategies |
| Description of the objectives of the strategies used to mitigate various types of risks of loss that may be incurred to meet future policy benefit obligations under long-duration contracts as they become due, and to offset possible losses arising from adverse movements in assumptions underlying reserve estimates, including assumed investment yields. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:LongDurationContractsHedgingStrategies |