| Standard label: | Mine Reclamation and Closing Liability, Noncurrent |
| Name: | us-gaap:MineReclamationAndClosingLiabilityNoncurrent |
| Documentation: | Amount of a reclamation and mine closing liability that is associated with a legal obligation for the closure and reclamation of a mine including the removal of buildings, equipment, machinery and other physical remnants of mining, closure of tailings impoundments, leach pads and other mine features, and contouring, covering and revegetation of waste rock piles and other disturbed areas. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:MineReclamationAndClosingLiabilityNoncurrent |
| Label | Role | Language |
| Mine Reclamation and Closing Liability, Noncurrent | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 450 20 S99 1 (SAB TOPIC 5.Y.Q2) | http://fasb.org/us-gaap/role/ref/legacyRef | 450 |
| Part Of Roll Up: |
| us-gaap:AssetRetirementObligationsNoncurrent |