cm:Concept: us-gaap:OperatingLeasesFutureMinimumPaymentsDueInRollingAfterYearFive
| Operating Leases, Future Minimum Payments, Due in Rolling after Year Five |
| us-gaap:OperatingLeasesFutureMinimumPaymentsDueInRollingAfterYearFive |
| Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due after the fifth 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:OperatingLeasesFutureMinimumPaymentsDueInRollingAfterYearFive |