| Name | IncreaseDecreaseInFossilFuelInventoriesAbstract |
|---|---|
| Namespace | http://fasb.org/us-gaap/2020-01-31 |
| Prefix | us-gaap |
| Data type | xbrli:stringItemType |
| Period type | duration |
| Substitution Group | xbrli:item |
| Balance | None |
| Nillable | True |
| Abstract | True |
| Text | Lang | Role | Container role |
|---|---|---|---|
| Increase (Decrease) in Fossil Fuel Inventories [Abstract] | en-US | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Name | Relation Type | Role | |
|---|---|---|---|
us-gaap:IncreaseDecreaseInCoalInventories | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfCashFlowsIndirect | |
us-gaap:IncreaseDecreaseInOtherFossilFuelInventories | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfCashFlowsIndirect | |
us-gaap:IncreaseDecreaseInFossilFuelInventories | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfCashFlowsIndirect | |
us-gaap:IncreaseDecreaseInCoalInventories | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfCashFlowsIndirectStatementTable | |
us-gaap:IncreaseDecreaseInOtherFossilFuelInventories | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfCashFlowsIndirectStatementTable | |
us-gaap:IncreaseDecreaseInFossilFuelInventories | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfCashFlowsIndirectStatementTable |
| Name | Relation Type | Role | |
|---|---|---|---|
us-gaap:IncreaseDecreaseInFuelInventoriesAbstract | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfCashFlowsIndirect | |
us-gaap:IncreaseDecreaseInFuelInventoriesAbstract | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfCashFlowsIndirectStatementTable |