cm:Concept: us-gaap:BusinessCombinationGoodwillRecognizedDescription
| Business Combination, Goodwill Recognized, Description |
| us-gaap:BusinessCombinationGoodwillRecognizedDescription |
| This element represents a qualitative description of the factors that make up the goodwill recognized in a business combination, such as expected synergies by the entity to be derived from combining operations of the acquiree, intangible assets that do not qualify for separate recognition, and such other factors as may apply. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:BusinessCombinationGoodwillRecognizedDescription |