Derivatives and Hedge Accounting Activities (Schedule of Offsetting Liabilities) (Detail) - USD ($) $ in Millions		Jun. 30, 2024	Dec. 31, 2023
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	$ 835	$ 697
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		511	250
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	30
Net Amounts		324	417
Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	152	240
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		25	27
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	30
Net Amounts		127	183
Commodity Contract | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	92	266
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		39	26
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	30
Net Amounts		53	210
Commodity Contract | Over-the-counter | Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	25	153
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		17	13
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	30
Net Amounts		8	110
Commodity Contract | Exchange
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	95	33
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		95	33
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	0
Net Amounts		0	0
Commodity Contract | Exchange | Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	4	3
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		4	3
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	0
Net Amounts		0	0
Interest Rate Contract | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	112	359
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		1	186
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	0
Net Amounts		111	173
Interest Rate Contract | Over-the-counter | Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	112	45
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		1	6
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	0
Net Amounts		111	39
Foreign currency exchange rate | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	536	39
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		376	5
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	0
Net Amounts		160	34
Foreign currency exchange rate | Over-the-counter | Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	11	39
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		3	5
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	0
Net Amounts		$ 8	$ 34

[1] Excludes derivative liabilities of $4 million at Dominion Energy at June 30, 2024 and $47 million and $76 million at Virginia Power at June 30, 2024 and December 31, 2023, respectively, which are not subject to master netting or similar arrangements. Dominion Energy did not have any derivative liabilities at December 31, 2023 which were not subject to master netting or similar arrangements.