cm:Concept: us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths
| Lessee, Operating Lease, Liability, Payments, Due Next Rolling Twelve Months |
| us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths |
| Amount of lessee's undiscounted obligation for lease payments for operating lease, due in next 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:LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths |