cm:Concept: us-gaap:MultiemployerPlanCollectiveBargainingArrangementRequiredPercentageOfContributions
| Multiemployer Plan, Collective-Bargaining Arrangement, Required Percentage of Contributions |
| us-gaap:MultiemployerPlanCollectiveBargainingArrangementRequiredPercentageOfContributions |
| Percentage of contributions required by collective bargaining arrangement to all contributions required of employer for pension and other postretirement 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 |
| Percent (num:percentItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:MultiemployerPlanCollectiveBargainingArrangementRequiredPercentageOfContributions |