cm:Level3TextBlock: us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivableMaturityTableTextBlock
| Sales-type and Direct Financing Leases, Lease Receivable, Maturity [Table Text Block] |
| us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivableMaturityTableTextBlock |
| Tabular disclosure of maturity of undiscounted cash flows to be received on annual basis for sales-type and direct financing leases receivable. Includes, but is not limited to, reconciliation to lease receivable recognized in statement of financial position. |
| cm:Level3TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivableMaturityTableTextBlock |