cm:Level3TextBlock: us-gaap:ShortdurationInsuranceContractsScheduleOfHistoricalClaimsDurationTableTextBlock
| Short-duration Insurance Contracts, Schedule of Historical Claims Duration [Table Text Block] |
| us-gaap:ShortdurationInsuranceContractsScheduleOfHistoricalClaimsDurationTableTextBlock |
| Tabular disclosure of average annual percentage payout of incurred claims by age, after reinsurance, for short-duration insurance contracts. |
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| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
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| us-gaap:ShortdurationInsuranceContractsScheduleOfHistoricalClaimsDurationTableTextBlock |