cm:Concept: us-gaap:DiscontinuationOfPriceRiskCashFlowHedge
| Discontinuation of Price Risk Cash Flow Hedge |
| us-gaap:DiscontinuationOfPriceRiskCashFlowHedge |
| Description of discontinued price risk cash flow hedge relationships, including identification of hedged items and hedging instruments. Includes reasons for the discontinuation of the cash flow hedge and the effects of such discontinuation on the financial statements. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:DiscontinuationOfPriceRiskCashFlowHedge |