cm:Concept: us-gaap:EmployeeStockOwnershipPlanESOPNumberOfAllocatedShares
| Employee Stock Ownership Plan (ESOP), Number of Allocated Shares |
| us-gaap:EmployeeStockOwnershipPlanESOPNumberOfAllocatedShares |
| The shares or units in an ESOP trust that have been assigned to individual participant accounts based on a known formula. IRS rules require allocations to be nondiscriminatory generally based on compensation, length of service, or a combination of both. For any particular participant such shares or units may be vested, unvested, or partially vested. |
| cm:Concept |
| Shares (xbrli:sharesItemType) |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:EmployeeStockOwnershipPlanESOPNumberOfAllocatedShares |