cm:Concept: us-gaap:CapitalLeasesFutureMinimumPaymentsDueInRollingYearThree
| Capital Leases, Future Minimum Payments, Due in Rolling Year Three |
| us-gaap:CapitalLeasesFutureMinimumPaymentsDueInRollingYearThree |
| Amount of minimum lease payments for capital leases due in the third 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:CapitalLeasesFutureMinimumPaymentsDueInRollingYearThree |