cm:Concept: us-gaap:ProceedsFromSaleAndCollectionOfNotesReceivable
| Proceeds from Sale and Collection of Notes Receivable |
| us-gaap:ProceedsFromSaleAndCollectionOfNotesReceivable |
| The cash inflow associated with the proceeds from sale of notes receivable, as well as principal collections from a borrowing supported by a written promise to pay an obligation (note receivable). |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:ProceedsFromSaleAndCollectionOfNotesReceivable |