cm:Concept: us-gaap:BusinessAcquisitionRevenueReportedByAcquiredEntityForLastAnnualPeriod
| Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period |
| us-gaap:BusinessAcquisitionRevenueReportedByAcquiredEntityForLastAnnualPeriod |
| Total revenue reported by the acquired entity for its previous full fiscal year before the business acquisition. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:BusinessAcquisitionRevenueReportedByAcquiredEntityForLastAnnualPeriod |