cm:Concept: us-gaap:FinanceLeaseLiabilityPaymentsDueInRollingYearFive
| Finance Lease, Liability, Payments, Due in Rolling Year Five |
| us-gaap:FinanceLeaseLiabilityPaymentsDueInRollingYearFive |
| Amount of lessee's undiscounted obligation for lease payments for finance lease, due in fifth rolling twelve months following latest statement of financial position date. For interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:FinanceLeaseLiabilityPaymentsDueInRollingYearFive |