Details for Selection
| Standard label: | Coal Supply Agreement Obligation, Noncurrent |
| Name: | us-gaap:CoalSupplyAgreementObligationNoncurrent |
| Documentation: | Noncurrent liability of coal supply agreement. |
| Commentary: | |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As of (instant) |
| Balance type: | Credit |
| Object class: | [Concept] |