cm:Concept: us-gaap:DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent
| Deferred Compensation Cash-based Arrangements, Liability, Current and Noncurrent |
| us-gaap:DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent |
| Aggregate carrying value as of the balance sheet date of the liabilities for deferred compensation arrangements. Represents currently earned compensation under cash arrangements (such as a profit-sharing plan, rabbi trust, and employee contract--excluding equity-based arrangements) that is not actually paid until a later date. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent |