cm:Concept: us-gaap:WorkersCompensationLiabilityNoncurrent
| Workers' Compensation Liability, Noncurrent |
| us-gaap:WorkersCompensationLiabilityNoncurrent |
| Carrying value as of the balance sheet date of obligations and payables pertaining to claims incurred of a workers compensation nature. Used to reflect the noncurrent portion of the liabilities (due beyond one year; or beyond one operating cycle if longer). |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:WorkersCompensationLiabilityNoncurrent |