cm:Concept: us-gaap:MultiemployerPlansCollectiveBargainingArrangementExpirationDateDescription
| Multiemployer Plans, Collective-Bargaining Arrangement, Description |
| us-gaap:MultiemployerPlansCollectiveBargainingArrangementExpirationDateDescription |
| Description of the significant collective-bargaining arrangements within the range of expiration dates for collective-bargaining arrangements requiring contributions to a multiemployer plan as well as other information to help investors understand the significance of the collective-bargaining agreements and when they expire. 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:MultiemployerPlansCollectiveBargainingArrangementExpirationDateDescription |