Accumulated Other Comprehensive Income (Loss) (Schedule of Changes in AOCI Net of Tax and Reclassifications out of AOCI by Component) (Detail) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2024		Jun. 30, 2023		Jun. 30, 2024		Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]					$ 27,529
Total other comprehensive income (loss)		$ 57		$ (1)		(181)		$ 6
Ending balance		27,073				27,073
Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		21,876		17,299		21,657	[2]	16,949
Income before income tax expense		596		420		1,189		872
Total other comprehensive income (loss)		4		5		7		0
Ending balance		22,359		17,638		22,359		17,638
Total Derivative-Hedging Activities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(202)	[3],[4]	(250)	[3],[4]	(216)	[5],[6]	(249)	[5],[6]
Other comprehensive income (loss) before reclassifications: gains (losses)		2	[3],[4]	6	[3],[4]	9	[5],[6]	(3)	[5],[6]
Income tax expense (benefit)		(2)	[3],[4]	(2)	[3],[4]	(6)	[5],[6]	(5)	[5],[6]
Total, net of tax		9	[3],[4]	8	[3],[4]	16	[5],[6]	16	[5],[6]
Total other comprehensive income (loss)		11	[3],[4]	14	[3],[4]	25	[5],[6]	13	[5],[6]
Ending balance	[3],[4],[6]	(191)		(236)		(191)		(236)
Total Derivative-Hedging Activities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		22	[7],[8]	7	[7],[8]	15	[9],[10]	16	[9],[10]
Other comprehensive income (loss) before reclassifications: gains (losses)		2	[7],[8]	6	[7],[8]	9	[9],[10]	(3)	[9],[10]
Income (loss) before income tax expense	[3],[8]			0
Income tax expense (benefit)		0	[3],[8]	0	[7],[8]	0	[9],[10]	0	[9],[10]
Total, net of tax		0	[3],[8]	0	[7],[8]	0	[9],[10]	0	[9],[10]
Total other comprehensive income (loss)		2	[7],[8]	6	[7],[8]	9	[9],[10]	(3)	[9],[10]
Ending balance	[7],[8],[10]	24		13		24		13
Total Derivative-Hedging Activities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges (benefit)		11	[3],[4]	10	[3],[4]	22	[5],[6]	21	[5],[6]
Other income (expense)		0	[3],[4]	0	[3],[4]	0	[5],[6]	0	[5],[6]
Income (loss) before income tax expense		11	[3],[4]	10	[3],[4]	22	[5],[6]	21	[5],[6]
Total Derivative-Hedging Activities | Reclassification out of Accumulated Other Comprehensive Income | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)	[9],[10]					0
Income (loss) before income tax expense		0	[7],[8]			0	[9],[10]	0	[9],[10]
Investment Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(20)	[11]	(26)	[11]	0	[12]	(44)	[12]
Other comprehensive income (loss) before reclassifications: gains (losses)		7	[11]	(1)	[11]	(19)	[12]	16	[12]
Income tax expense (benefit)		0	[11]	1	[11]	(2)	[12]	0	[12]
Total, net of tax		0	[11]	(2)	[11]	6	[12]	(1)	[12]
Total other comprehensive income (loss)		7	[11]	(3)	[11]	(13)	[12]	15	[12]
Ending balance	[11],[12]	(13)		(29)		(13)		(29)
Investment Securities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(3)	[13]	(3)	[13]	1	[14]	(7)	[14]
Other comprehensive income (loss) before reclassifications: gains (losses)		1	[13]	(1)	[13]	(4)	[14]	3	[14]
Income (loss) before income tax expense	[13]			0
Income tax expense (benefit)		1	[13]	0	[13]	0	[14]	0	[14]
Total, net of tax		1	[13]	0	[13]	2	[14]	0	[14]
Total other comprehensive income (loss)		2	[13]	(1)	[13]	(2)	[14]	3	[14]
Ending balance	[13],[14]	(1)		(4)		(1)		(4)
Investment Securities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges (benefit)		0	[11]	0	[11]	0	[12]	0	[12]
Other income (expense)		0	[11]	(3)	[11]	8	[12]	(1)	[12]
Income (loss) before income tax expense		0	[11]	(3)	[11]	8	[12]	(1)	[12]
Investment Securities | Reclassification out of Accumulated Other Comprehensive Income | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)	[14]					2
Income (loss) before income tax expense		0	[13]			2	[14]	0	[14]
Pension and Other Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,522)	[15]	(1,287)	[15]	(1,290)	[16]	(1,276)	[16]
Other comprehensive income (loss) before reclassifications: gains (losses)		(16)	[15]	0	[15]	(253)	[16]	0	[16]
Income tax expense (benefit)		(20)	[15]	4	[15]	(21)	[16]	8	[16]
Total, net of tax		55	[15]	(12)	[15]	60	[16]	(23)	[16]
Total other comprehensive income (loss)		39	[15]	(12)	[15]	(193)	[16]	(23)	[16]
Ending balance	[15],[16]	(1,483)		(1,299)		(1,483)		(1,299)
Pension and Other Postretirement Benefit Costs | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges (benefit)		0	[15]	0	[15]	0	[16]	0	[16]
Other income (expense)		75	[15]	(16)	[15]	81	[16]	(31)	[16]
Income (loss) before income tax expense		75	[15]	(16)	[15]	81	[16]	(31)	[16]
Equity Method Investees
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		0	[17]	(2)	[17]	0	[18]	(3)	[18]
Other comprehensive income (loss) before reclassifications: gains (losses)		0	[17]	0	[17]	0	[18]	1	[18]
Income tax expense (benefit)		0	[17]	0	[17]	0	[18]	0	[18]
Total, net of tax		0	[17]	0	[17]	0	[18]	0	[18]
Total other comprehensive income (loss)		0	[17]	0	[17]	0	[18]	1	[18]
Ending balance	[17],[18]	0		(2)		0		(2)
Equity Method Investees | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges (benefit)		0	[17]	0	[17]	0	[18]	0	[18]
Other income (expense)		0	[17]	0	[17]	0	[18]	0	[18]
Income (loss) before income tax expense		0	[17]	0	[17]	0	[18]	0	[18]
AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,744)		(1,565)		(1,506)		(1,572)
Other comprehensive income (loss) before reclassifications: gains (losses)		(7)		5		(263)		14
Income tax expense (benefit)		(22)		3		(29)		3
Total, net of tax		64		(6)		82		(8)
Total other comprehensive income (loss)		57		(1)		(181)		6
Ending balance		(1,687)		(1,566)		(1,687)		(1,566)
AOCI | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		19		4		16		9
Other comprehensive income (loss) before reclassifications: gains (losses)		3		5		5		0
Income (loss) before income tax expense				0
Income tax expense (benefit)		1		0		0		0
Total, net of tax		1		0		2		0
Total other comprehensive income (loss)		4		5		7		0
Ending balance		23		9		23		9
AOCI | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges (benefit)		11		10		22		21
Other income (expense)		75		(19)		89		(32)
Income (loss) before income tax expense		86		$ (9)		111		(11)
AOCI | Reclassification out of Accumulated Other Comprehensive Income | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)						2
Income (loss) before income tax expense		$ 0				$ 2		$ 0

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

[2] Virginia Power’s Consolidated Balance Sheet at December 31, 2023 has been derived from the audited Consolidated Balance Sheet at that date.

[3] Comprised entirely of interest rate derivative hedging activities.

[4] Net of $64 million, $68 million, $79 million and $83 million tax at June 30, 2024, March 31, 2024, June 30, 2023 and March 31, 2023, respectively.

[5] Comprised entirely of interest rate derivative hedging activities.

[6] Net of $64 million, $73 million, $79 million and $83 million tax at June 30, 2024, December 31, 2023, June 30, 2023 and December 31, 2022, respectively.

[7] Comprised entirely of interest rate derivative hedging activities.

[8] Net of $(8) million, $(7) million, $(4) million and $(2) million tax at June 30, 2024, March 31, 2024, June 30, 2023 and March 31, 2023, respectively.

[9] Comprised entirely of interest rate derivative hedging activities.

[10] Net of $(8) million, $(5) million, $(4) million and $(5) million tax at June 30, 2024, December 31, 2023, June 30, 2023 and December 31, 2022, respectively.

[11] Net of $3 million, $6 million, $9 million and $6 million tax at June 30, 2024, March 31, 2024, June 30, 2023 and March 31, 2023, respectively.

[12] Net of $3 million, $(2) million, $9 million and $13 million tax at June 30, 2024, December 31, 2023, June 30, 2023 and December 31, 2022, respectively.

[13] Net of $— million tax at June 30, 2024 and $1 million tax at March 31, 2024, June 30, 2023, and March 31, 2023, respectively.

[14] Net of $— million, $— million, $1 million and $2 million tax at June 30, 2024, December 31, 2023, June 30, 2023 and December 31, 2022, respectively.

[15] Net of $522 million, $538 million, $453 million and $449 million tax at June 30, 2024, March 31, 2024, June 30, 2023 and March 31, 2023, respectively.

[16] Net of $522 million, $456 million, $453 million and $445 million tax at June 30, 2024, December 31, 2023, June 30, 2023 and December 31, 2022, respectively.

[17] Net of $— million tax at June 30, 2024, March 31, 2024, June 30, 2023 and March 31, 2023, respectively.

[18] Net of $— million tax at June 30, 2024, December 31, 2023, June 30, 2023 and $1 million tax at December 31, 2022, respectively.