cm:Concept: us-gaap:UnamortizedDiscountsOnAcceptancesResold
| Unamortized Discounts on Acceptances Resold |
| us-gaap:UnamortizedDiscountsOnAcceptancesResold |
| The amount of the unamortized discount or expense related to the financial institution's sale of short-term negotiable time drafts drawn on and accepted by the institution (also known as Banker's Acceptances) in the secondary market. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:UnamortizedDiscountsOnAcceptancesResold |