Property, Plant and Equipment (Narrative) (Detail) $ in Millions		1 Months Ended		3 Months Ended	12 Months Ended
	Nov. 08, 2023 USD ($)	Feb. 29, 2024 USD ($)	Dec. 31, 2021 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2023 USD ($) MW	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Aug. 31, 2021 USD ($)
Property Plant And Equipment [Line Items]
Impairment of assets and other charges					$ 307	$ 1,401	$ 194
CVOW Commercial Project Excluding Financing Costs | Forecast
Property Plant And Equipment [Line Items]
Total project costs		$ 9,800
Maximum | Forecast
Property Plant And Equipment [Line Items]
Additional capital contribution percentage		83.00%
Maximum | CVOW Commercial Project Excluding Financing Costs Condition Two | Forecast
Property Plant And Equipment [Line Items]
Total project costs		$ 11,300
Minimum | Forecast
Property Plant And Equipment [Line Items]
Additional capital contribution percentage		67.00%
Dominion Energy
Property Plant And Equipment [Line Items]
Impairment of assets and other charges						908
Asset impairment charges after tax						685
Property, plant and equipment, intangible assets and right-of-use lease assets down to estimated fair value						665
Virginia Power and Stonepeak | CVOW Commercial Project | Forecast
Property Plant And Equipment [Line Items]
Remaining capital percentage		50.00%
Virginia Power and Stonepeak | Maximum | Forecast
Property Plant And Equipment [Line Items]
Total project costs		$ 11,300
Corporate Office Building
Property Plant And Equipment [Line Items]
Sale of office building					40
Level 3 | Corporate Office Building
Property Plant And Equipment [Line Items]
Long-lived assets, estimated fair value			$ 26		35		26
Impairment of Assets and Other Charges | Corporate Office Building
Property Plant And Equipment [Line Items]
Impairment of assets and other charges					93		16
Asset impairment charges after tax					69		12
Terra Nova Renewable Partners | Nonregulated Solar Projects | S B L Holdco L L C
Property Plant And Equipment [Line Items]
Percentage of controlling interest								67.00%
Disposal group, total value of consideration								$ 456
Gain (loss) on held for sale			$ (149)
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]			Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property
Gain (loss) on held for sale, after tax			$ (89)
Clearway Energy Inc | Four Brothers And Three Cedars
Property Plant And Equipment [Line Items]
Percentage of controlling interest								50.00%
Disposal group, total value of consideration								$ 335
Gain (loss) on held for sale			$ (364)
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]			Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property
Gain (loss) on held for sale, after tax			$ (81)
Virginia Electric and Power Company
Property Plant And Equipment [Line Items]
Project easement cost paid	$ 65
Easement charges before tax	65
Easement charges after tax	$ 49
Virginia Electric and Power Company | Forecast
Property Plant And Equipment [Line Items]
Percentage of proceeds from sale of non controlling interests in CVOW commercial project		50.00%
Termination fee		$ 200
Virginia Electric and Power Company | CVOW Commercial Project | Forecast
Property Plant And Equipment [Line Items]
Ownership percentage		50.00%
Virginia Electric and Power Company | CVOW Commercial Project Excluding Financing Costs | Forecast
Property Plant And Equipment [Line Items]
Initial withholding amount		$ 100
Virginia Electric and Power Company | CVOW Commercial Project Excluding Financing Costs Condition Two | Forecast
Property Plant And Equipment [Line Items]
Proceeds from sale of non controlling interests in CVOW commercial project		3,000
Virginia Electric and Power Company | Minimum | Forecast
Property Plant And Equipment [Line Items]
Total project costs		13,700
Virginia Electric and Power Company | Minimum | CVOW Commercial Project | Forecast
Property Plant And Equipment [Line Items]
Initial withholding amount		145
Virginia Electric and Power Company | Virginia Regulation
Property Plant And Equipment [Line Items]
Impairment of assets and other charges							$ 318
Virginia Electric and Power Company | Impairment of Assets and Other Charges
Property Plant And Equipment [Line Items]
Impairment of assets and other charges				$ 191
Asset impairment charges after tax				$ 142
Stonepeak | Maximum | Forecast
Property Plant And Equipment [Line Items]
Total project costs		13,700
Additional capital costs		11,300
Stonepeak | Minimum | Forecast
Property Plant And Equipment [Line Items]
Total project costs		$ 11,300
Acquisition of Solar Project at Schools in Virginia
Property Plant And Equipment [Line Items]
Anticipated projected cost					$ 16
Aggregate generation capacity | MW					7
Project cost					$ 7
Aggregate generation capacity of service solar facilities | MW					4
Utility Property
Property Plant And Equipment [Line Items]
Sale of utility property					$ 12	20
Gain on sale of asset					11	20
Gain on sale of asset after tax					$ 8	$ 15