cm:Level3TextBlock: us-gaap:ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock
| Schedule of Amounts Recognized in Balance Sheet [Table Text Block] |
| us-gaap:ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock |
| Tabular disclosure of the amounts that are recognized in the balance sheet (or statement of financial position) for pension plans and/or other employee benefit plans, showing separately the assets and current and noncurrent liabilities (if applicable) recognized. |
| cm:Level3TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock |
| AmountsRecognizedInBalanceSheet |