cm:Member: us-gaap:MultiemployerPlansTypeDomain
| Multiemployer Plans Type [Domain] |
| us-gaap:MultiemployerPlansTypeDomain |
| Types of pension or postretirement benefit plans to which two or more unrelated employers contribute to the same plan where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. Types of multiemployer plans include pension benefit plans and postretirement benefit plans. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:MultiemployerPlansTypeDomain |