cm:Concept: us-gaap:ForeignCurrencyTranslationAdjustmentDescription
| Foreign Currency Translation Adjustment, Description |
| us-gaap:ForeignCurrencyTranslationAdjustmentDescription |
| Describes the nature of the translation adjustment. Includes an analysis of the change during the period in the accumulated adjustment and explanation of items creating the change. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ForeignCurrencyTranslationAdjustmentDescription |