cm:Concept: us-gaap:DiscontinuedOperationNatureOfAdjustmentToPriorPeriodGainLossOnDisposal
| Discontinued Operation, Nature of Adjustment to Prior Period Gain (Loss) on Disposal |
| us-gaap:DiscontinuedOperationNatureOfAdjustmentToPriorPeriodGainLossOnDisposal |
| Description of the adjustment to an amount previously reported in discontinued operations that is directly related to the disposal of a discontinued operation in a prior period. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:DiscontinuedOperationNatureOfAdjustmentToPriorPeriodGainLossOnDisposal |