cm:Concept: us-gaap:DescriptionOfAccountingMethodUsedForForeignCurrencyDerivatives
| Description of Accounting Method Used for Foreign Currency Derivatives |
| us-gaap:DescriptionOfAccountingMethodUsedForForeignCurrencyDerivatives |
| General discussion of the accounting for foreign currency exchange rate derivatives. Includes discussion of where derivatives and the gain (loss) on derivatives are reported in the financial statements. Also includes discussion of any hedge designations used, 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:DescriptionOfAccountingMethodUsedForForeignCurrencyDerivatives |