cm:Concept: us-gaap:DescriptionOfTypesOfInterestRateCashFlowHedgingInstrumentsUsed
| Description of Types of Interest Rate Cash Flow Hedging Instruments Used |
| us-gaap:DescriptionOfTypesOfInterestRateCashFlowHedgingInstrumentsUsed |
| Description of the types of interest rate derivative instruments designated as hedging instruments in cash flow hedges. For example, swaps, caps, floors, and collars. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:DescriptionOfTypesOfInterestRateCashFlowHedgingInstrumentsUsed |