cm:Concept: us-gaap:ConcentrationRiskAvailabilityOfServices
| Concentration Risk, Availability of Services |
| us-gaap:ConcentrationRiskAvailabilityOfServices |
| Description of risks that arise due to the entity's reliance on a particular service used in its operations and the availability of that service. At a minimum, the description informs financial statement users of the general nature of the risk. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ConcentrationRiskAvailabilityOfServices |