cm:Concept: us-gaap:IncreaseDecreaseInRestructuringReserve
| Increase (Decrease) in Restructuring Reserve |
| us-gaap:IncreaseDecreaseInRestructuringReserve |
| The increase (decrease) during the period in the carrying amount (including both current and noncurrent portions of the accrual) of the liability pertaining to the exit from or disposal of business activities or restructuring pursuant to a duly authorized plan, excluding costs or losses pertaining to an entity newly acquired in a business combination and to asset retirement obligations. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:IncreaseDecreaseInRestructuringReserve |