cm:Concept: us-gaap:ObligationToReturnSecuritiesReceivedAsCollateral
| Obligation to Return Securities Received as Collateral |
| us-gaap:ObligationToReturnSecuritiesReceivedAsCollateral |
| The fair value of collateral received by the entity associated with securities borrowed that must be returned if the counterparty fulfills its obligations. It appears on the balance sheet as a liability and has a corresponding asset that appears on the balance sheet called Securities Received as Collateral. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:ObligationToReturnSecuritiesReceivedAsCollateral |