cm:Level2TextBlock: us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsEstimationMethodologyPolicy
| Premiums Receivable, Allowance for Doubtful Accounts, Estimation Methodology, Policy [Policy Text Block] |
| us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsEstimationMethodologyPolicy |
| Disclosure of accounting policy for determining the estimated allowance for doubtful accounts for premium amounts due from policyholders, insureds, and other insurance entities. May include factors that management considered, such as historical loss experience and current economic and competitive conditions. |
| cm:Level2TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsEstimationMethodologyPolicy |