cm:Level3TextBlock: us-gaap:ScheduleOfForeignExchangeContractsStatementOfFinancialPositionTableTextBlock
| Schedule of Foreign Exchange Contracts, Statement of Financial Position [Table Text Block] |
| us-gaap:ScheduleOfForeignExchangeContractsStatementOfFinancialPositionTableTextBlock |
| Tabular disclosure of the presentation of foreign exchange contracts on the statement of financial position, including the fair value amounts and location of such amounts. |
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| (no balance type) |
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| us-gaap:ScheduleOfForeignExchangeContractsStatementOfFinancialPositionTableTextBlock |