cm:Concept: us-gaap:ProceedsFromLoanAndLeaseOriginationsAndPrincipalCollections1
| Proceeds from Loan and Lease Originations and Principal Collections |
| us-gaap:ProceedsFromLoanAndLeaseOriginationsAndPrincipalCollections1 |
| Cash inflow related to a loan origination (the process when securing a mortgage for a piece of real property), lease origination, and principal collections. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:ProceedsFromLoanAndLeaseOriginationsAndPrincipalCollections1 |