cm:Level2TextBlock: us-gaap:AnticipatedInvestmentIncomeAsComponentOfPremiumDeficiencyOnShortDurationContractsPolicy
| Anticipated Investment Income as Component of Premium Deficiency on Short Duration Contracts, Policy [Policy Text Block] |
| us-gaap:AnticipatedInvestmentIncomeAsComponentOfPremiumDeficiencyOnShortDurationContractsPolicy |
| Disclosure of accounting policy for including anticipated yield on investments as a component of calculating premium deficiency on short-duration insurance contracts. |
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| Text Block (HTML) (nonnum:textBlockItemType) |
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| us-gaap:AnticipatedInvestmentIncomeAsComponentOfPremiumDeficiencyOnShortDurationContractsPolicy |