cm:Level2TextBlock: us-gaap:IntangibleAssetsArisingFromInsuranceContractsAcquiredInBusinessCombinationPolicyPolicyTextBlock
| Intangible Assets Arising from Insurance Contracts Acquired in Business Combination, Policy [Policy Text Block] |
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| Disclosure of accounting policy for measuring intangible assets arising from insurance and reinsurance contracts acquired in a business combination. This disclosure describes the amortization method used in connection with a business combination entered into on or after December 15, 2008. |
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| us-gaap:IntangibleAssetsArisingFromInsuranceContractsAcquiredInBusinessCombinationPolicyPolicyTextBlock |