cm:Concept: us-gaap:LessorOperatingLeasePaymentsToBeReceivedNextRollingTwelveMonths
| Lessor, Operating Lease, Payments to be Received, Next Rolling Twelve Months |
| us-gaap:LessorOperatingLeasePaymentsToBeReceivedNextRollingTwelveMonths |
| Amount of lease payments to be received by lessor in next rolling twelve months following latest statement of financial position date for operating lease. For interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:LessorOperatingLeasePaymentsToBeReceivedNextRollingTwelveMonths |