IndexCoal Contract [Member]
| Name | CoalContractMember |
|---|---|
| Namespace | http://fasb.org/us-gaap/2022 |
| Prefix | us-gaap |
| Data type | dtr-types:domainItemType |
| Period type | duration |
| Substitution Group | xbrli:item |
| Balance | None |
| Nillable | True |
| Abstract | True |
Labels
| Text | Lang | Role | Container role |
|---|---|---|---|
| Coal Contract [Member] | en-US | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Derivative instrument whose primary underlying risk is tied to coal. | en-US | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
References
| Name | Value | Role |
|---|---|---|
| elementCreationTaxonomyVersion | 2012 | http://fasb.org/us-gaap/role/tin/taxonomyImplementationNote |