cm:Concept: us-gaap:FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase
| Federal Funds Purchased and Securities Sold under Agreements to Repurchase |
| us-gaap:FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase |
| Amount after offset of short term borrowing where a bank borrows, at the federal funds rate, from another bank and securities that an entity sells and agrees to repurchase at a specified date for a specified price. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase |