cm:Concept: us-gaap:DescriptionOfLocationOfGainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsInFinancialStatements
| Description of Location of Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments in Financial Statements |
| us-gaap:DescriptionOfLocationOfGainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsInFinancialStatements |
| Description of where the net gain (loss) on interest rate derivatives not designated as hedging instruments are reported in the statement of income or other statement of financial performance. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:DescriptionOfLocationOfGainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsInFinancialStatements |