 | us-gaap:ElectricityGenerationMember | domain-member | http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists |
 | us-gaap:ElectricityPurchasedMember | domain-member | http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists |
 | us-gaap:ElectricityUsRegulatedMember | domain-member | http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists |
 | us-gaap:ElectricDistributionMember | domain-member | http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists |
 | us-gaap:ElectricTransmissionMember | domain-member | http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists |
 | us-gaap:CostOfGoodsSoldElectric | dep-dimensionallyQualifiedConcept-deprecatedConcept | http://fasb.org/us-gaap/role/deprecated/deprecated |
 | us-gaap:ElectricUtilityRevenue | dep-dimensionallyQualifiedConcept-deprecatedConcept | http://fasb.org/us-gaap/role/deprecated/deprecated |
 | us-gaap:ElectricityGenerationMember | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncome |
 | us-gaap:ElectricityPurchasedMember | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncome |
 | us-gaap:ElectricityUsRegulatedMember | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncome |
 | us-gaap:ElectricDistributionMember | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncome |
 | us-gaap:ElectricTransmissionMember | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncome |
 | us-gaap:ElectricityGenerationMember | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeStatementTable |
 | us-gaap:ElectricityPurchasedMember | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeStatementTable |
 | us-gaap:ElectricityUsRegulatedMember | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeStatementTable |
 | us-gaap:ElectricDistributionMember | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeStatementTable |
 | us-gaap:ElectricTransmissionMember | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeStatementTable |