cm:Concept: us-gaap:CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldDisposalsOfLoans
| Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Disposals of Loans |
| us-gaap:CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldDisposalsOfLoans |
| Sale or transfer of a loan during the period resulting in a reduction in the excess of a loan's cash flows expected to be collected over the investor's initial investment. This relates to loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAccretableYieldDisposalsOfLoans |