cm:Concept: us-gaap:SecuritiesPurchasedUnderAgreementsToResellRepaymentThroughOperationOrSaleOfCollateralCollateralExtensibleList
| Securities Purchased under Agreements to Resell, Repayment through Operation or Sale of Collateral, Collateral [Extensible List] |
| us-gaap:SecuritiesPurchasedUnderAgreementsToResellRepaymentThroughOperationOrSaleOfCollateralCollateralExtensibleList |
| Indicates type of collateral for securities purchased under agreement to resell, for which repayment is expected through operation or sale of collateral and borrower is experiencing financial difficulty. |
| cm:Concept |
| srt-types:extensibleListItemType |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:SecuritiesPurchasedUnderAgreementsToResellRepaymentThroughOperationOrSaleOfCollateralCollateralExtensibleList |