cm:Table: us-gaap:ScheduleOfFairValueOffBalanceSheetRisksTable
| Schedule of Fair Value, Off-balance Sheet Risks [Table] |
| us-gaap:ScheduleOfFairValueOffBalanceSheetRisksTable |
| Schedule detailing the information required and determined to be disclosed regarding the fair value of financial assets and financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition. |
| cm:Table |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:ScheduleOfFairValueOffBalanceSheetRisksTable |