cm:Concept: us-gaap:DescriptionOfFairValueHedgeAccountingMethod
| Description of Fair Value Hedge Accounting Method |
| us-gaap:DescriptionOfFairValueHedgeAccountingMethod |
| General discussion of the accounting for fair value hedges. Includes discussion of where derivatives and the gain (loss) on derivatives are reported in the financial statements. Also includes discussion of the assessment of hedge effectiveness and measurement of hedge ineffectiveness. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:DescriptionOfFairValueHedgeAccountingMethod |