cm:Concept: us-gaap:DeferredCompensationArrangementWithIndividualRecordedLiability
| Deferred Compensation Arrangement with Individual, Recorded Liability |
| us-gaap:DeferredCompensationArrangementWithIndividualRecordedLiability |
| The carrying amount of the liability as of the balance sheet date to an individual under a deferred compensation arrangement. This amount may be the result of periodic accruals made over the period of active employment, or reflect termination benefits resulting contractual terms or a death benefit. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:DeferredCompensationArrangementWithIndividualRecordedLiability |