cm:Level3TextBlock: us-gaap:ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock
| Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block] |
| us-gaap:ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock |
| Tabular disclosure of the effective portion of the gains and losses on derivative instruments designated (and non-derivative instruments) designated and qualifying in cash flow hedges and net investment hedges that was recognized in other comprehensive income (loss) during the current period. |
| cm:Level3TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock |