cm:Level2TextBlock: us-gaap:CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyOngoingBenefitArrangements
| Costs Associated with Exit or Disposal Activity or Restructuring, Ongoing Benefit Arrangement [Policy Text Block] |
| us-gaap:CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyOngoingBenefitArrangements |
| Disclosure of accounting policy for cost associated with exit or disposal activity or restructuring incurred according to terms of ongoing benefit arrangement. Excludes entity newly acquired in business combination or discontinued operation. |
| cm:Level2TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyOngoingBenefitArrangements |