cm:Concept: us-gaap:BusinessCombinationContingentConsiderationArrangementsBasisForAmount
| Business Combination, Contingent Consideration Arrangements, Basis for Amount |
| us-gaap:BusinessCombinationContingentConsiderationArrangementsBasisForAmount |
| For contingent consideration arrangements recognized in connection with a business combination, this element represents a description of the basis for determining the amount of the payment recorded. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:BusinessCombinationContingentConsiderationArrangementsBasisForAmount |