Derivatives and Hedge Accounting Activities (Schedule of Offsetting Liabilities) (Detail) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	$ 697	$ 1,404
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		250	435
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		30	396
Net Amounts		417	573
Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	240	430
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		27	45
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		30	247
Net Amounts		183	138
Commodity Contract | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	266	443
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		26	34
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		30	71
Net Amounts		210	338
Commodity Contract | Over-the-counter | Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	153	146
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		13	13
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		30	71
Net Amounts		110	62
Commodity Contract | Exchange
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	33	483
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		33	159
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	324
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]	3	176
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		3	0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	176
Net Amounts		0	0
Interest Rate Contract | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	39	377
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		5	210
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	1
Net Amounts		34	166
Interest Rate Contract | Over-the-counter | Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	39	7
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		5	0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	0
Net Amounts		34	7
Foreign currency exchange rate | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Liabilities Presented in the Consolidated Balance Sheet	[1]	359	101
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		186	32
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	0
Net Amounts		173	69
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]	45	101
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		6	32
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0	0
Net Amounts		$ 39	$ 69

[1] Excludes derivative liabilities of $76 million and $26 million at Virginia Power at December 31, 2023 and 2022, respectively, which are not subject to master netting or similar arrangements. Dominion Energy did not have any derivative liabilities at December 31, 2023 or 2022 which were not subject to master netting or similar arrangements.