cm:Concept: us-gaap:DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedGross
| Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Gross |
| us-gaap:DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedGross |
| Amount, before effects of master netting arrangements, of derivative liabilities, securities sold under agreements to repurchase and securities loaned. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedGross |