cm:Level3TextBlock: us-gaap:ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock
| Derivatives Not Designated as Hedging Instruments [Table Text Block] |
| us-gaap:ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock |
| Tabular disclosure of derivative instrument not designated or qualifying as hedging instrument. |
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| us-gaap:ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock |