| Name | CertainMethaneGasReservesProvedReservesQuantity |
|---|---|
| Namespace | http://fasb.org/us-gaap/2020-01-31 |
| Prefix | us-gaap |
| Data type | num:volumeItemType |
| Period type | instant |
| Substitution Group | xbrli:item |
| Balance | None |
| Nillable | True |
| Abstract | False |
| Text | Lang | Role | Container role |
|---|---|---|---|
| Certain Methane Gas Reserves, Proved Reserves, Quantity (Deprecated 2018-01-31) | en-US | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| The quantity of proved reserves related to methane gas that are deemed to be economically producible only as a consequence of existing Federal tax incentives. | en-US | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Name | Value | Role |
|---|---|---|
| DeprecatedDate | 2018-01-31 | http://fasb.org/srt/role/changeNote/changeNote |
| DeprecatedLabel | Element was deprecated because the guidance from which this element is derived is no longer applicable. | http://fasb.org/srt/role/changeNote/changeNote |
| TaxonomyVersion | 2018 | http://fasb.org/srt/role/changeNote/changeNote |
| ChangeDate | 2017-08 | http://fasb.org/srt/role/changeNote/changeNote |
| ElementDeprecated | true | http://fasb.org/srt/role/changeNote/changeNote |
| Name | Relation Type | Role | |
|---|---|---|---|
us-gaap:DeprecatedItems | parent-child | http://fasb.org/us-gaap/role/deprecated/deprecated |