cm:Concept: us-gaap:CapitalLeasesFutureMinimumPaymentsDueInRollingYearFour
| Capital Leases, Future Minimum Payments, Due in Rolling Year Four |
| us-gaap:CapitalLeasesFutureMinimumPaymentsDueInRollingYearFour |
| Amount of minimum lease payments for capital leases due in the fourth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:CapitalLeasesFutureMinimumPaymentsDueInRollingYearFour |