cm:Concept: us-gaap:VariableInterestEntityNonconsolidatedComparisonOfCarryingAmountOfAssetsAndLiabilitiesToMaximumLossExposureExplanationQualitativeInformation
| Variable Interest Entity, Nonconsolidated, Comparison of Carrying Amount of Assets and Liabilities to Maximum Loss Exposure, Explanation, Qualitative Information |
| us-gaap:VariableInterestEntityNonconsolidatedComparisonOfCarryingAmountOfAssetsAndLiabilitiesToMaximumLossExposureExplanationQualitativeInformation |
| Description of the differences between the carrying amounts of assets and liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary, and the reporting entity's maximum exposure to loss as a result of its involvement with the VIE. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:VariableInterestEntityNonconsolidatedComparisonOfCarryingAmountOfAssetsAndLiabilitiesToMaximumLossExposureExplanationQualitativeInformation |