cm:Table: us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTable
| Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table] |
| us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTable |
| Disclosure of information about financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) using recurring unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. |
| cm:Table |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTable |