cm:Concept: us-gaap:ExtinguishmentOfDebtNatureOfRestrictionsOnAssetsSetAsideForScheduledPayments
| Extinguishment of Debt, Nature of Restrictions on Assets Set Aside for Scheduled Payments |
| us-gaap:ExtinguishmentOfDebtNatureOfRestrictionsOnAssetsSetAsideForScheduledPayments |
| Describes restrictions on any assets set aside solely for the purpose of satisfying scheduled payments of a specific obligation, thus freeing the obligor of the responsibility for making payments. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ExtinguishmentOfDebtNatureOfRestrictionsOnAssetsSetAsideForScheduledPayments |