cm:Concept: us-gaap:RevenuePerformanceObligationDescriptionOfPaymentTerms
| Revenue, Performance Obligation, Description of Payment Terms |
| us-gaap:RevenuePerformanceObligationDescriptionOfPaymentTerms |
| Description of payment terms in contract with customer. Includes, but is not limited to, timing of payment, existence of financing component, variability of consideration and constraint on variable consideration. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:RevenuePerformanceObligationDescriptionOfPaymentTerms |