cm:Concept: us-gaap:ProceedsFromSaleAndCollectionOfMortgageNotesReceivable
| Proceeds from Sale and Collection of Mortgage Notes Receivable |
| us-gaap:ProceedsFromSaleAndCollectionOfMortgageNotesReceivable |
| The cash inflow from proceeds from sale of receivables arising from the mortgage note on real estate; includes collections on mortgage notes receivable that are not classified as operating cash flows. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:ProceedsFromSaleAndCollectionOfMortgageNotesReceivable |