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