cm:Concept: us-gaap:ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleSegmentClassification
| Impaired Assets to be Disposed of by Method Other than Sale, Segment Classification |
| us-gaap:ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleSegmentClassification |
| The segment in which the impaired long-lived asset being disposed of by a method other than sale is reported. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleSegmentClassification |