cm:Concept: us-gaap:RevenuePerformanceObligationDescriptionOfTiming
| Revenue, Performance Obligation, Description of Timing |
| us-gaap:RevenuePerformanceObligationDescriptionOfTiming |
| Description of timing for satisfying performance obligation in contract with customer. Includes, but is not limited to, as services are rendered, and upon shipment, delivery or completion of service. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:RevenuePerformanceObligationDescriptionOfTiming |