cm:Concept: us-gaap:FairValueOfSecuritiesReceivedAsCollateralThatHaveBeenResoldOrRepledged
| Fair Value of Securities Received as Collateral that Have Been Resold or Repledged |
| us-gaap:FairValueOfSecuritiesReceivedAsCollateralThatHaveBeenResoldOrRepledged |
| Fair value of the collateral, or portion thereof, that has been re-pledged, delivered, or otherwise used. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:FairValueOfSecuritiesReceivedAsCollateralThatHaveBeenResoldOrRepledged |