cm:Member: us-gaap:PropertyAndCasualtyCommercialInsuranceProductLineMember
| Property and Casualty, Commercial Insurance [Member] |
| us-gaap:PropertyAndCasualtyCommercialInsuranceProductLineMember |
| Contract providing insurance coverage to policyholder on commercial property against property-related loss. Includes, but is not limited to, damage, theft, or legal liability for personal injury. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:PropertyAndCasualtyCommercialInsuranceProductLineMember |