cm:Concept: us-gaap:ImpairedIntangibleAssetFactsAndCircumstancesLeadingToImpairment
| Impaired Intangible Asset, Facts and Circumstances Leading to Impairment |
| us-gaap:ImpairedIntangibleAssetFactsAndCircumstancesLeadingToImpairment |
| Description of the underlying cause of impairment of the intangible asset, such as loss of value due to technological obsolescence. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ImpairedIntangibleAssetFactsAndCircumstancesLeadingToImpairment |