cm:Level3TextBlock: us-gaap:ScheduleOfIntercompanyForeignCurrencyBalancesTextBlock
| Schedule of Intercompany Foreign Currency Balances [Table Text Block] |
| us-gaap:ScheduleOfIntercompanyForeignCurrencyBalancesTextBlock |
| Tabular disclosure of long-term intercompany foreign balances, including related intercompany entity, underlying foreign currencies and amounts of intercompany foreign currency transactions that are of a long-term investment nature (that is settlement is not planned or anticipated in the foreseeable future), as of the balance sheet date. |
| cm:Level3TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
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| us-gaap:ScheduleOfIntercompanyForeignCurrencyBalancesTextBlock |
| IntercompanyForeignCurrencyBalance |