cm:Concept: us-gaap:DecommissioningLiabilityNoncurrent
| Decommissioning Liability, Noncurrent |
| us-gaap:DecommissioningLiabilityNoncurrent |
| Amount of a decommissioning liability associated with a legal obligation that a firm incurs when it constructs or operates an asset that must eventually be withdrawn from active service. This may include operating assets such as nuclear power plants or shipping vessels. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:DecommissioningLiabilityNoncurrent |