XML 37 R100.htm IDEA: XBRL DOCUMENT
v3.19.3

Regulatory Matters (Narrative) (Detail) ft³ in Millions, customer in Millions, $ in Millions |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Nov. 01, 2019 USD ($) | May 03, 2019 USD ($) | May 31, 2019 USD ($) | Apr. 30, 2019 ft³ | Mar. 31, 2019 USD ($) | Feb. 28, 2019 USD ($) | Jan. 31, 2019 USD ($) | Oct. 31, 2018 USD ($) | Jul. 31, 2018 USD ($) | Nov. 30, 2013 kV mi | Mar. 31, 2019 USD ($) | Dec. 31, 2017 customer | Dec. 31, 2011 | Dec. 31, 2018 USD ($)
SCE&G [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Recover of cost and net lost revenue with incentive |  |  |  |  |  |  | $ 30 |  |  |  |  |  |  |
Virginia Electric and Power Company |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Submitted and approved decrease in base rate revenue |  |  |  |  |  |  |  | $ 14 |  |  |  |  |  |
Regulatory liabilities one time bill credit amount |  |  |  |  |  |  |  | 13 |  |  |  |  |  |
Virginia Electric and Power Company | Virginia Regulation |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proposed annual revenue reduction amount |  |  |  |  |  |  | $ 171 |  |  |  |  |  |  |
Interim rate reduction amount |  |  |  |  |  |  |  |  | $ 125 |  |  |  |  |
Annual revenue reduction amount |  |  |  |  | $ 183 |  |  |  |  |  |  |  |  |
Estimated annual revenue reduction on one-time customer credit |  |  |  |  | $ 135 |  |  |  |  |  |  |  |  |
Return of equity percentage |  |  |  |  | 10.75% |  |  |  |  |  |  |  |  |
Virginia Electric and Power Company | Virginia Regulation | Surry Switching Station Transmission Line |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Length of transmission line (miles) | mi |  |  |  |  |  |  |  |  |  | 7 |  |  |  |
Capacity of transmission line (kV) | kV |  |  |  |  |  |  |  |  |  | 500 |  |  |  |
Virginia Electric and Power Company | Virginia Regulation | Transmission Line from Skiffes Creek Switching Station to Wheaton Substation |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Length of transmission line (miles) | mi |  |  |  |  |  |  |  |  |  | 20 |  |  |  |
Capacity of transmission line (kV) | kV |  |  |  |  |  |  |  |  |  | 230 |  |  |  |
Virginia Electric and Power Company | Virginia Regulation | Rider U |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proposed revenue requirement |  |  |  |  | $ 52 |  |  |  |  |  |  |  |  |
Projected capital investment |  |  |  |  |  |  |  |  |  |  | $ 123 |  |  |
Virginia Electric and Power Company | Virginia Regulation | DSM Programs |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proposed revenue requirement |  |  |  |  |  |  |  | 49 |  |  |  |  |  |
Projected capital investment |  |  |  |  |  |  |  | 262 |  |  |  |  |  |
Increase (decrease) in revenue requirement |  |  |  |  |  |  |  | $ 18 |  |  |  |  |  |
Virginia Electric and Power Company | Virginia Regulation | Rider C3A |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proposed revenue requirement |  |  | $ 49 |  |  |  |  |  |  |  |  |  |  |
Virginia Electric and Power Company | Virginia Regulation | Solar Development Project | Rider US-3 | Operating Segments |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proposed revenue requirement |  |  |  |  |  |  |  |  | $ 10 |  |  |  |  |
Virginia Electric and Power Company | North Carolina Regulation |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Return of equity percentage |  |  |  |  | 10.75% |  |  |  |  |  |  |  |  |
Percentage of earned return |  |  |  |  | 7.52% |  |  |  |  |  |  |  |  |
Authorized return percentage |  |  |  |  | 9.90% |  |  |  |  |  |  |  |  |
Virginia Electric and Power Company | North Carolina Regulation | Annual Base Fuel Revenues |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase (decrease) in revenue requirement | $ 27 |  |  |  |  |  |  |  |  |  |  |  |  |
East Ohio | Ohio Regulation | Pipeline Infrastructure Replacement Program |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proposed revenue requirement |  |  |  |  |  | $ 190 |  |  |  |  |  |  |  |
Percentage replacement of pipeline system |  |  |  |  |  | 25.00% |  |  |  |  |  |  |  |
Total estimated cost |  |  |  |  |  | $ 1,600 |  |  |  |  |  |  |  | $ 202
East Ohio | Ohio Regulation | Automated Meter Reading Program |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proposed revenue requirement |  |  |  |  | $ 4 |  |  |  |  |  |  |  |  |
Number of customers with automated meter reading technology | customer |  |  |  |  |  |  |  |  |  |  |  | 1.2 |  |
East Ohio | Ohio Regulation | CEP Program |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proposed revenue requirement |  | $ 83 |  |  |  |  |  |  |  |  |  |  |  |
Total estimated cost |  | $ 723 |  |  |  |  |  |  |  |  |  |  |  |
Percentage to defer expenses on capital investments |  |  |  |  |  |  |  |  |  |  |  |  | 6.50% |
Questar Gas | Utah And Wyoming Regulation |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
LNG storage facility, liquefaction rate per day | ft³ |  |  |  | 8.2 |  |  |  |  |  |  |  |  |  |
Number of days to make prudency determination |  |  |  | 180 days |  |  |  |  |  |  |  |  |  |
Cove Point | Federal Energy Regulatory Commission |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Utilities General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Annual transportation cost rate adjustment, approval amount requested to recover amount |  |  |  |  |  | $ 24 |  |  |  |  |  |  |  |

X
- Definition Annual revenue reduction amount. + References No definition available. + Details
Name: | d_AnnualRevenueReductionAmount
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Estimated annual revenue reduction on one-time customer credit. + References No definition available. + Details
Name: | d_EstimatedAnnualRevenueReductionOnOneTimeCustomerCredit
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Kilo Volt Line + References No definition available. + Details
Name: | d_KiloVoltLine
Namespace Prefix: | d_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Liquefied natural gas storage facility liquefaction rate per day. + References No definition available. + Details
Name: | d_LiquefiedNaturalGasStorageFacilityLiquefactionRatePerDay
Namespace Prefix: | d_
Data Type: | num:volumeItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of days to make prudency determination. + References No definition available. + Details
Name: | d_NumberOfDaysToMakePrudencyDetermination
Namespace Prefix: | d_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage to defer expenses on capital investments. + References No definition available. + Details
Name: | d_PercentageToDeferExpensesOnCapitalInvestments
Namespace Prefix: | d_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public utilities annual revenue reduction amount. + References No definition available. + Details
Name: | d_PublicUtilitiesAnnualRevenueReductionAmount
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Public utilities annual transportation cost rate adjustment approval request to recover amount. + References No definition available. + Details
Name: | d_PublicUtilitiesAnnualTransportationCostRateAdjustmentApprovalRequestToRecoverAmount
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Public utilities authorized rate percentage. + References No definition available. + Details
Name: | d_PublicUtilitiesAuthorizedRatePercentage
Namespace Prefix: | d_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public utilities interim rate reduction amount. + References No definition available. + Details
Name: | d_PublicUtilitiesInterimRateReductionAmount
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Public utilities, length of transmission line. + References No definition available. + Details
Name: | d_PublicUtilitiesLengthOfTransmissionLine
Namespace Prefix: | d_
Data Type: | num:lengthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public utilities, number of customers with updated automated meter reading technology. + References No definition available. + Details
Name: | d_PublicUtilitiesNumberOfCustomersWithUpdatedAutomatedMeterReadingTechnology
Namespace Prefix: | d_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public utilities, percentage replacement of pipeline system. + References No definition available. + Details
Name: | d_PublicUtilitiesPercentageReplacementOfPipelineSystem
Namespace Prefix: | d_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Public Utilities, Requested Rate, Amount + References No definition available. + Details
Name: | d_PublicUtilitiesRequestedRateAmount
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Recovery of cost and net lost revenues with incentive. + References No definition available. + Details
Name: | d_RecoveryOfCostAndNetLostRevenuesWithIncentive
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Regulatory liabilities one time bill credit amount. + References No definition available. + Details
Name: | d_RegulatoryLiabilitiesOneTimeBillCreditAmount
Namespace Prefix: | d_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The increase (decrease) during the period in the costs deferred for rate-making purposes. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44264-110382 + Details
Name: | us-gaap_PhaseInPlanNetChangeInAmountOfCostsDeferredForRateMakingPurposes
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of public utility's approved rate increase (decrease) by regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of public utility's approved rate increase (decrease) by regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedRateIncreaseDecreasePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discloses the amount of construction work in process that is included in the rate making process at period end. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfConstructionWorkInProcessIncludedInRateBase
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of public utility's requested rate increase (decrease) with regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of public utility's requested return on equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedReturnOnEquityPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=d_SCEAndGMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=d_VirginiaElectricAndPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=d_VirginiaRegulationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=d_SurrySwitchingStationTransmissionLineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=d_TransmissionLineFromSkiffesCreekSwitchingStationToWheatonSubstationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=d_RiderUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=d_DsmProgramsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=d_RiderC3aMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=d_SolarDevelopmentProjectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=d_RiderUS3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=d_NorthCarolinaRegulationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=d_AnnualBaseFuelRevenuesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=d_EastOhioMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=d_OhioRegulationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=d_PipelineInfrastructureReplacementProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=d_AutomatedMeterReadingProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=d_CapitalExpenditureProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=d_QuestarGasCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=d_UtahAndWyomingRegulationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=d_DominionCovePointLNGLPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=d_FederalEnergyRegulatoryCommissionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |