cm:Concept: us-gaap:NaturePurposeAndEffectOfReinsuranceTransactions
| Nature, Purpose and Effect of Reinsurance Transactions |
| us-gaap:NaturePurposeAndEffectOfReinsuranceTransactions |
| Description of the coverages that are ceded, explanation that the purpose of reinsurance is primarily to mitigate risk of loss under the policies ceded, and to explain in text the effects of reinsurance on the entity's financial statements and operations. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:NaturePurposeAndEffectOfReinsuranceTransactions |