cm:Level3TextBlock: us-gaap:ScheduleOfQuantitativeInformationAboutFinancialAssetsAndAssociatedLiabilitiesAccountedForAsSecuredBorrowingsTextBlock
| Schedule of Assets and Associated Liabilities Accounted for as Secured Borrowings [Table Text Block] |
| us-gaap:ScheduleOfQuantitativeInformationAboutFinancialAssetsAndAssociatedLiabilitiesAccountedForAsSecuredBorrowingsTextBlock |
| Tabular disclosure of the carrying amount and classification of assets and liabilities recognized in the transferor's statement of financial position at the end of each period presented. |
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| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
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| us-gaap:ScheduleOfQuantitativeInformationAboutFinancialAssetsAndAssociatedLiabilitiesAccountedForAsSecuredBorrowingsTextBlock |