cm:Table: us-gaap:PolicyholderAccountBalanceGuaranteedMinimumCreditingRateTable
| Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Table] |
| us-gaap:PolicyholderAccountBalanceGuaranteedMinimumCreditingRateTable |
| Disclosure of information about policyholder account balance by range of guaranteed minimum crediting rate and related range of difference between rate being credited to policyholder and respective guaranteed minimum. |
| cm:Table |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:PolicyholderAccountBalanceGuaranteedMinimumCreditingRateTable |