cm:Concept: us-gaap:NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationDueDateDayMonthAndYear
| Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Due Date |
| us-gaap:NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationDueDateDayMonthAndYear |
| Date of maturity, expiration or mandatory redemption of the financial or equity instrument issued as noncash or part noncash consideration for a business or asset acquired, in CCYY-MM-DD format. |
| cm:Concept |
| Date (xbrli:dateItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationDueDateDayMonthAndYear |