Investments (Equity and Fixed Income Securities, Insurance Contracts and Cash Equivalents in Decommissioning Trust Funds) (Detail) - USD ($) $ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Fair Value		$ 2,170
Cash equivalents and other, Amortized Cost	[1]	41	$ 84
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]	41	84
Amortized Cost, Total		3,765	3,699
Total Unrealized Gains		3,913	3,308
Total Unrealized Losses	[2]	(70)	(61)
Allowance for Credit Losses, Total		0	0
Fair Value, Total		7,608	6,946	[3]
Net assets related to pending sales of securities		27	49
Fair value of securities in an unrealized loss position		1,300	764
Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Fair Value		1,291
Cash equivalents and other, Amortized Cost	[1]	18	47
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]	18	47
Amortized Cost, Total		2,073	2,033
Total Unrealized Gains		2,031	1,726
Total Unrealized Losses	[2]	(45)	(43)
Allowance for Credit Losses, Total		0	0
Fair Value, Total		4,059	3,716	[4]
Net assets related to pending sales of securities		17	27
Fair value of securities in an unrealized loss position		738	384
Corporate Debt Fixed Income Securities
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	591	508
Fixed income securities Total Unrealized Gains	[5]	5	10
Fixed income securities Total Unrealized Losses	[5]	(25)	(27)
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	571	491
Corporate Debt Fixed Income Securities | Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	365	292
Fixed income securities Total Unrealized Gains	[5]	2	3
Fixed income securities Total Unrealized Losses	[5]	(20)	(21)
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	347	274
Government Debt Fixed Income Securities
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	1,505	1,426
Fixed income securities Total Unrealized Gains	[5]	11	28
Fixed income securities Total Unrealized Losses	[5]	(38)	(24)
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	1,478	1,430
Government Debt Fixed Income Securities | Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	877	811
Fixed income securities Total Unrealized Gains	[5]	6	17
Fixed income securities Total Unrealized Losses	[5]	(19)	(12)
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	864	816
Other
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	121
Fixed income securities Total Unrealized Gains	[5]	0
Fixed income securities Total Unrealized Losses	[5]	0
Fixed income securities Allowance for Credit Losses	[5]	0
Fixed income securities Fair Value	[5]	121
Other | Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	80
Fixed income securities Total Unrealized Gains	[5]	0
Fixed income securities Total Unrealized Losses	[5]	0
Fixed income securities Allowance for Credit Losses	[5]	0
Fixed income securities Fair Value	[5]	80
Insurance Contracts
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	243	244
Fixed income securities Total Unrealized Gains	[5]	0	0
Fixed income securities Total Unrealized Losses	[5]	0	0
Fixed income securities Fair Value	[5]	243	244
U.S.
Debt Securities, Available-for-Sale [Line Items]
Equity securities Amortized Cost	[6]	1,264	1,276
Equity securities Total Unrealized Gains	[6]	3,897	3,270
Equity securities Total Unrealized Losses	[6]	(7)	(10)
Equity securities Fair Value	[6]	5,154	4,536
U.S. | Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Equity securities Amortized Cost	[6]	733	759
Equity securities Total Unrealized Gains	[6]	2,023	1,706
Equity securities Total Unrealized Losses	[6]	(6)	(10)
Equity securities Fair Value	[6]	2,750	2,455
Common/collective trust funds | Fixed Income
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	0	161
Fixed income securities Total Unrealized Gains	[5]	0	0
Fixed income securities Total Unrealized Losses	[5]	0	0
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	0	161
Common/collective trust funds | Fixed Income | Virginia Electric and Power Company
Debt Securities, Available-for-Sale [Line Items]
Fixed income securities Amortized Cost, Total	[5]	0	124
Fixed income securities Total Unrealized Gains	[5]	0	0
Fixed income securities Total Unrealized Losses	[5]	0	0
Fixed income securities Allowance for Credit Losses	[5]	0	0
Fixed income securities Fair Value	[5]	$ 0	$ 124

[1] Dominion Energy includes pending sales of securities of $27 million and $49 million at June 30, 2024 and December 31, 2023, respectively. Virginia Power includes pending sales of securities of $17 million and $27 million at June 30, 2024, and December 31, 2023, respectively.

[2] Dominion Energy’s fair value of securities in an unrealized loss position was $1.3 billion and $764 million at June 30, 2024 and December 31, 2023, respectively. Virginia Power’s fair value of securities in an unrealized loss position was $738 million and $384 million at June 30, 2024 and December 31, 2023, respectively.

[3] Dominion Energy’s Consolidated Balance Sheet at December 31, 2023 has been derived from the audited Consolidated Balance Sheet at that date.

[4] Virginia Power’s Consolidated Balance Sheet at December 31, 2023 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] Unrealized gains and losses on equity securities are included in other income (expense) and the nuclear decommissioning trust regulatory liability.