Regulatory Matters (Narrative) (Detail 1) shares in Millions, $ in Millions		1 Months Ended													3 Months Ended				6 Months Ended		9 Months Ended	12 Months Ended				24 Months Ended
	Nov. 08, 2023 USD ($)	Sep. 30, 2024 USD ($)	Nov. 30, 2023 USD ($)	Oct. 31, 2023 USD ($) Project MW	Jul. 31, 2023 USD ($) shares	May 31, 2023 USD ($)	Apr. 30, 2023 USD ($)	Mar. 31, 2023 USD ($) Project Components	Oct. 31, 2022 USD ($) Project MW	May 31, 2022 USD ($)	Oct. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Apr. 30, 2020 USD ($) MW	Nov. 30, 2013 mi kV	Dec. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Sep. 30, 2022	Dec. 31, 2023 USD ($) Battery	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2024	Dec. 31, 2022 USD ($)
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																						$ 307	$ 1,401	$ 194
Impairment of assets and other charges (benefits)																								25
Proposed capital cost of energy storage system															$ 16,540							16,540	15,179				$ 15,179
Depreciation and amortization																						2,580	2,442	2,117
Generation And Distribution Services
Public Utilities General Disclosures [Line Items]
Authorized return percentage					9.70%
Virginia Regulation
Public Utilities General Disclosures [Line Items]
Cap on revenue reductions in triennial review																								50
Percentage of electric energy excluding existing nuclear generation and certain new carbon resources													100.00%
Cap on revenue reductions in the first triennial													$ 50
Authorized return percentage					9.35%
Percentage of earned return					9.04%
Virginia Regulation | Securitization Option | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement																						541
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Authorized but unissued shares of common stock | shares					3,250
Number of electric distribution grid transformation projects | Project								14
Number of electric distribution grid transformation projects components | Components								6
Proposed capital cost of energy storage system															14,268							14,268	13,034				$ 13,034
Depreciation and amortization																						1,871	$ 1,736	1,364
Virginia Electric and Power Company | Impairment of Assets and Other Charges
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																	$ 191
Impairment of assets and other charges after tax																	142
Virginia Electric and Power Company | Impairment of Assets and Other Charges (Benefits)
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																		$ 76
Impairment of assets and other charges after tax																		$ 56
Virginia Electric and Power Company | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement						$ 13
Virginia Electric and Power Company | Rider RGGI | Impairment of Assets and Other Charges
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																	180
Impairment of assets and other charges (benefits) after tax																	$ 134
Depreciation and amortization																$ 33
Depreciation and amortization after tax																$ 25
Virginia Electric and Power Company | Income Payment Program
Public Utilities General Disclosures [Line Items]
Total revenue requirement												$ 93
Universal service fee				$ 71
Virginia Electric and Power Company | Grid Transformation And Security Act | Impairment of Assets and Other Charges
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																									$ 130
Impairment of assets and other charges (benefits)																								130
Impairment of assets and other charges (benefits) after tax																								97
Virginia Electric and Power Company | Utility-scale Solar
Public Utilities General Disclosures [Line Items]
Targeted capacity provided by legislation | MW				329					474
Number of utility-scale projects | Project				4					8
Proposed cost of project				$ 850					$ 1,200
Virginia Electric and Power Company | Energy Storage
Public Utilities General Disclosures [Line Items]
Targeted capacity provided by legislation | MW									16
Virginia Electric and Power Company | Electric Distribution Grid Transformation Projects
Public Utilities General Disclosures [Line Items]
Proposed cost of project								$ 1,100							773							773
Proposed operations and maintenance investment								$ 71														$ 71
Number of battery energy storage system | Battery																						5
Batteries to be installed over number of years																						5 years
Proposed capital cost of energy storage system															$ 50							$ 50
Virginia Electric and Power Company | Virginia Regulation
Public Utilities General Disclosures [Line Items]
Rate year beginning					2023-07
Estimated under-recovered balances	$ 1,300																		$ 1,300
Increase (decrease) in revenue requirement											$ 330
Public utilities event costs to be recovered			$ 45
Impairment of assets and other charges																								318
Refund to customer over 6 month period											255
Refund to customer three years											75
Authorized return percentage					9.70%		9.70%
Authorized return percentage credited to customers bills							1.50%
Credited to customers bills percentage							100.00%
Capitalization ratio					52.10%		52.10%								52.10%
Increase (Decrease) Over Previous Year											309
Virginia Electric and Power Company | Virginia Regulation | Operating Revenue
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																								356
Impairment of assets and other charges after tax																								265
Virginia Electric and Power Company | Virginia Regulation | Regulatory Asset Associated with Early Retirements
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																								549
Impairment of assets and other charges after tax																								409
Virginia Electric and Power Company | Virginia Regulation | Impairment of Assets and Other Charges (Benefits)
Public Utilities General Disclosures [Line Items]
Impairment of assets and other charges																								318
Impairment of assets and other charges after tax																								$ 237
Virginia Electric and Power Company | Virginia Regulation | Base Rate Case
Public Utilities General Disclosures [Line Items]
Total revenue requirement					$ 350	351	$ 350
Increase (decrease) in revenue requirement											$ 50
Authorized return percentage											9.35%
Virginia Electric and Power Company | Virginia Regulation | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Total revenue requirement						$ 2,300				$ 2,300
Rate year beginning						2023-07				2022-07
Estimated under-recovered balances						$ 1,300				$ 1,000										$ 578
Increase (decrease) in revenue requirement										$ 1,800
Fuel cost recognized						3,300
Public utilities collection of requested under-recovered projected fuel expense period																				3 years	3 years
Public utilities collection of requested under-recovered projected fuel expense beginning date																					Jul. 01, 2022
Public utilities exclude from recovery through base rates one half of financing costs period																					3 years
Virginia Electric and Power Company | Virginia Regulation | Generation And Distribution Services
Public Utilities General Disclosures [Line Items]
Authorized return percentage			9.05%
Virginia Electric and Power Company | Virginia Regulation | Surry Switching Station Transmission Line
Public Utilities General Disclosures [Line Items]
Miles of Lines | mi														7
Type of Line | 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]
Miles of Lines | mi														20
Type of Line | kV														230
Virginia Electric and Power Company | Virginia Regulation | Forecast
Public Utilities General Disclosures [Line Items]
One-time credits to customers		$ 15
Virginia Electric and Power Company | Virginia Regulation | Proposed First Option | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Increase (decrease) in revenue requirement						631
Virginia Electric and Power Company | Virginia Regulation | Securitization Option | Annual Fuel Factor
Public Utilities General Disclosures [Line Items]
Estimated under-recovered balances						$ 1,300
Virginia Electric and Power Company | Virginia Regulation | Solar And Onshore Wind | End of Year 2035
Public Utilities General Disclosures [Line Items]
Targeted capacity provided by legislation | MW													16,100
Virginia Electric and Power Company | Virginia Regulation | Utility-scale Solar | By End of Year 2024
Public Utilities General Disclosures [Line Items]
Targeted capacity provided by legislation | MW													3,000
Virginia Electric and Power Company | Virginia Regulation | Small-scale Solar | End of Year 2035
Public Utilities General Disclosures [Line Items]
Targeted capacity provided by legislation | MW													1,100
Virginia Electric and Power Company | Virginia Regulation | Energy Storage | End of Year 2035
Public Utilities General Disclosures [Line Items]
Targeted capacity provided by legislation | MW													2,700
Virginia Electric and Power Company | Triennial Review
Public Utilities General Disclosures [Line Items]
Authorized return percentage							70.00%																				70.00%
Credited to customers bills percentage							85.00%
Virginia Electric and Power Company | Biennial Review
Public Utilities General Disclosures [Line Items]
Authorized return percentage					9.35%		9.35%
Authorized return percentage credited to customers bills							1.50%
Credited to customers bills percentage							85.00%
Virginia Electric and Power Company | Biennial Review | Forecast
Public Utilities General Disclosures [Line Items]
Authorized return percentage																										9.70%