cm:Concept: us-gaap:MultiemployerPlansPlanBenefitsDescription
| Multiemployer Plans, Plan Benefits, Description |
| us-gaap:MultiemployerPlansPlanBenefitsDescription |
| Description of the nature of multiemployer plan benefits as well as who is covered by the benefits. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:MultiemployerPlansPlanBenefitsDescription |