Investments (Equity and Fixed Income Securities, Insurance Contracts and Cash Equivalents in Decommissioning Trust Funds) (Detail) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Mar. 31, 2025	Dec. 31, 2024
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Fair Value		$ 2,269
Cash equivalents and other, Amortized Cost	[1]	55	$ 65
Cash equivalents and other, Total Unrealized Gains	[1]	0	0
Cash equivalents and other, Total Unrealized Losses	[1]	0	0
Cash equivalents and other, Allowance for Credit Losses	[1]	0	0
Cash equivalents and other, Fair Value	[1]	55	65
Amortized Cost, Total		3,860	3,828
Total Unrealized Gains		4,064	4,281
Total Unrealized Losses	[2]	(45)	(58)
Allowance for Credit Losses, Total		0	0
Fair Value, Total		7,879	8,051	[3]
Net assets related to pending sales of securities		25	35
Fair value of securities in an unrealized loss position		779	1,400
Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Fair Value		1,352
Cash equivalents and other, Amortized Cost	[1]	13	22
Cash equivalents and other, Total Unrealized Gains	[1]	0	0
Cash equivalents and other, Total Unrealized Losses	[1]	0	0
Cash equivalents and other, Allowance for Credit Losses	[1]	0	0
Cash equivalents and other, Fair Value	[1]	13	22
Amortized Cost, Total		2,112	2,092
Total Unrealized Gains		2,117	2,227
Total Unrealized Losses	[2]	(29)	(33)
Allowance for Credit Losses, Total		0	0
Fair Value, Total		4,200	4,286	[4]
Net assets related to pending sales of securities		13	22
Fair value of securities in an unrealized loss position		481	796
Corporate Debt Fixed Income Securities
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	516	516
Fixed income securities Total Unrealized Gains	[5]	8	6
Fixed income securities Total Unrealized Losses	[5]	(12)	(15)
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	512	507
Corporate Debt Fixed Income Securities | Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	305	303
Fixed income securities Total Unrealized Gains	[5]	3	3
Fixed income securities Total Unrealized Losses	[5]	(9)	(12)
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	299	294
Government Debt Fixed Income Securities
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	1,765	1,736
Fixed income securities Total Unrealized Gains	[5]	20	7
Fixed income securities Total Unrealized Losses	[5]	(28)	(39)
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	1,757	1,704
Government Debt Fixed Income Securities | Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	1,057	1,038
Fixed income securities Total Unrealized Gains	[5]	11	4
Fixed income securities Total Unrealized Losses	[5]	(16)	(18)
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	1,052	1,024
Insurance Contracts
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[6]	239	239
Fixed income securities Total Unrealized Gains	[6]	0	0
Fixed income securities Total Unrealized Losses	[6]	0	0
Fixed income securities Fair Value	[6]	239	239
U.S.
Debt Securities, Available-for-Sale [Line Items]
Equity securities Amortized Cost	[7]	1,234	1,220
Equity securities Total Unrealized Gains	[7]	3,927	4,157
Equity securities Total Unrealized Losses	[7]	(5)	(4)
Equity securities Fair Value	[7]	5,156	5,373
U.S. | Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Equity securities Amortized Cost	[7]	704	695
Equity securities Total Unrealized Gains	[7]	2,038	2,155
Equity securities Total Unrealized Losses	[7]	(4)	(3)
Equity securities Fair Value	[7]	2,738	2,847
International
Debt Securities, Available-for-Sale [Line Items]
Equity securities Amortized Cost	[7]	51	52
Equity securities Total Unrealized Gains	[7]	109	111
Equity securities Total Unrealized Losses	[7]	0	0
Equity securities Fair Value	[7]	160	163
International | Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Equity securities Amortized Cost	[7]	33	34
Equity securities Total Unrealized Gains	[7]	65	65
Equity securities Total Unrealized Losses	[7]		0
Equity securities Fair Value	[7]	$ 98	$ 99

[1] Dominion Energy includes pending sales of securities of $25 million and $35 million at March 31, 2025 and December 31, 2024, respectively. Virginia Power includes pending sales of securities of $13 million and $22 million at March 31, 2025, and December 31, 2024, respectively.

[2] Dominion Energy’s fair value of securities in an unrealized loss position was $779 million and $1.4 billion at March 31, 2025 and December 31, 2024, respectively. Virginia Power’s fair value of securities in an unrealized loss position was $481 million and $796 million at March 31, 2025 and December 31, 2024, respectively.

[3] Dominion Energy’s Consolidated Balance Sheet at December 31, 2024 has been derived from the audited Consolidated Balance Sheet at that date.

[4] Virginia Power’s Consolidated Balance Sheet at December 31, 2024 has been derived from the audited Consolidated Balance Sheet at that date.

[5] Unrealized gains and losses on fixed income securities are included in AOCI and the nuclear decommissioning trust regulatory liability. Changes in allowance for credit losses are included in other income (expense).

[6] Includes company owned life insurance contracts measured at cash surrender value.

[7] Unrealized gains and losses on equity securities are included in other income (expense) and the nuclear decommissioning trust regulatory liability.