cm:Concept: us-gaap:SubsidiaryOrEquityMethodInvesteeNatureOfOperations
| Subsidiary or Equity Method Investee, Nature of Operations |
| us-gaap:SubsidiaryOrEquityMethodInvesteeNatureOfOperations |
| Description of the major products or services that a subsidiary or equity investee sells or provides and its principal markets, including locations of those markets. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:SubsidiaryOrEquityMethodInvesteeNatureOfOperations |