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				9 Months Ended
		Sep. 30, 2024		Sep. 30, 2023		Sep. 30, 2024		Sep. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]					$ 27,529
Total other comprehensive income (loss)		$ 33		$ 1		(148)		$ 7
Ending balance		27,531				27,531
Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		22,359		17,638		21,657	[2]	16,949
Income before income tax expense		795		603		1,984		1,475
Total other comprehensive income (loss)		(2)		15		5		15
Ending balance		23,010		18,128		23,010		18,128
Total Derivative-Hedging Activities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(191)	[3],[4]	(236)	[3],[4]	(216)	[5],[6]	(249)	[5],[6]
Other comprehensive income (loss) before reclassifications: gains (losses)		(7)	[3],[4]	19	[3],[4]	2	[5],[6]	16	[5],[6]
Income tax expense (benefit)		(3)	[3],[4]	(3)	[3],[4]	(9)	[5],[6]	(8)	[5],[6]
Total, net of tax		8	[3],[4]	8	[3],[4]	24	[5],[6]	24	[5],[6]
Total other comprehensive income (loss)		1	[3],[4]	27	[3],[4]	26	[5],[6]	40	[5],[6]
Ending balance	[3],[4],[6]	(190)		(209)		(190)		(209)
Total Derivative-Hedging Activities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		24	[7],[8]	13	[7],[8]	15	[9],[10]	16	[9],[10]
Other comprehensive income (loss) before reclassifications: gains (losses)		(7)	[7],[8]	18	[7],[8]	2	[9],[10]	15	[9],[10]
Interest and related charges (benefit)	[7],[8]	0
Income tax expense (benefit)		0	[7],[8]	(1)	[3],[8]	0	[9],[10]	(1)	[9],[10]
Total, net of tax		0	[3],[8]	0	[7],[8]	0	[9],[10]	0	[9],[10]
Total other comprehensive income (loss)		(7)	[7],[8]	18	[7],[8]	2	[9],[10]	15	[9],[10]
Ending balance	[7],[8],[10]	17		31		17		31
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]	11	[3],[4]	33	[5],[6]	32	[5],[6]
Discontinued operations				0	[3],[4]			0	[5],[6]
Income (loss) before income tax expense		11	[3],[4]	11	[3],[4]	33	[5],[6]	32	[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]
Interest and related charges (benefit)				1	[7],[8]			1	[9],[10]
Income (loss) before income tax expense		0	[7],[8]	1	[3],[8]	0	[9],[10]	1	[9],[10]
Investment Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(13)	[11]	(29)	[11]	0	[12]	(44)	[12]
Other comprehensive income (loss) before reclassifications: gains (losses)		32	[11]	(22)	[11]	13	[12]	(6)	[12]
Income tax expense (benefit)		1	[11]	0	[11]	(1)	[12]	0	[12]
Total, net of tax		(1)	[11]	2	[11]	5	[12]	1	[12]
Total other comprehensive income (loss)		31	[11]	(20)	[11]	18	[12]	(5)	[12]
Ending balance	[11],[12]	18		(49)		18		(49)
Investment Securities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1)	[13]	(4)	[13]	1	[14]	(7)	[14]
Other comprehensive income (loss) before reclassifications: gains (losses)		6	[13]	(3)	[13]	2	[14]	0	[14]
Income tax expense (benefit)		(1)	[13]	0	[13]	(1)	[14]	0	[14]
Total, net of tax		(1)	[13]	0	[13]	1	[14]	0	[14]
Total other comprehensive income (loss)		5	[13]	(3)	[13]	3	[14]	0	[14]
Ending balance	[13],[14]	4		(7)		4		(7)
Investment Securities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Discontinued operations				0	[11]			0	[12]
Other income (expense)		(2)	[11]	2	[11]	6	[12]	1	[12]
Income (loss) before income tax expense		(2)	[11]	2	[11]	6	[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)		0	[13]	0	[13]	2	[14]	0	[14]
Income (loss) before income tax expense		0	[13]	0	[13]	2	[14]	0	[14]
Pension and Other Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,483)	[15]	(1,299)	[15]	(1,290)	[16]	(1,276)	[16]
Other comprehensive income (loss) before reclassifications: gains (losses)		4	[15]	0	[15]	(249)	[16]	0	[16]
Income tax expense (benefit)		1	[15]	7	[15]	(20)	[16]	15	[16]
Total, net of tax		(3)	[15]	(8)	[15]	57	[16]	(31)	[16]
Total other comprehensive income (loss)		1	[15]	(8)	[15]	(192)	[16]	(31)	[16]
Ending balance	[15],[16]	(1,482)		(1,307)		(1,482)		(1,307)
Pension and Other Postretirement Benefit Costs | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Discontinued operations				0	[15]			0	[16]
Other income (expense)		(4)	[15]	(15)	[15]	77	[16]	(46)	[16]
Income (loss) before income tax expense		(4)	[15]	(15)	[15]	77	[16]	(46)	[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]	(1)	[17]	0	[18]	0	[18]
Income tax expense (benefit)		0	[17]	(1)	[17]	0	[18]	(1)	[18]
Total, net of tax		0	[17]	3	[17]	0	[18]	3	[18]
Total other comprehensive income (loss)		0	[17]	2	[17]	0	[18]	3	[18]
Ending balance	[17],[18]	0		0		0		0
Equity Method Investees | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Discontinued operations				4	[17]			4	[18]
Other income (expense)		0	[17]	0	[17]	0	[18]	0	[18]
Income (loss) before income tax expense		0	[17]	4	[17]	0	[18]	4	[18]
AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,687)		(1,566)		(1,506)		(1,572)
Other comprehensive income (loss) before reclassifications: gains (losses)		29		(4)		(234)		10
Income tax expense (benefit)		(1)		3		(30)		6
Total, net of tax		4		5		86		(3)
Total other comprehensive income (loss)		33		1		(148)		7
Ending balance		(1,654)		(1,565)		(1,654)		(1,565)
AOCI | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		23		9		16		9
Other comprehensive income (loss) before reclassifications: gains (losses)		(1)		15		4		15
Income tax expense (benefit)		(1)		(1)		(1)		(1)
Total, net of tax		(1)		0		1		0
Total other comprehensive income (loss)		(2)		15		5		15
Ending balance		21		24		21		24
AOCI | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges (benefit)		11		11		33		32
Discontinued operations				4				4
Other income (expense)		(6)		(13)		83		(45)
Income (loss) before income tax expense		5		2		116		(9)
AOCI | Reclassification out of Accumulated Other Comprehensive Income | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges (benefit)		0		1				1
Other income (expense)		0		0		2		0
Income (loss) before income tax expense		$ 0		$ 1		$ 2		$ 1

[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, $64 million, $70 million and $79 million tax at September 30, 2024, June 30, 2024, September 30, 2023 and June 30, 2023, respectively.

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

[6] Net of $64 million, $73 million, $70 million and $83 million tax at September 30, 2024, December 31, 2023, September 30, 2023 and December 31, 2022, respectively.

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

[8] Net of $(6) million, $(8) million, $(11) million and $(4) million tax at September 30, 2024, June 30, 2024, September 30, 2023 and June 30, 2023, respectively.

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

[10] Net of $(6) million, $(5) million, $(11) million and $(5) million tax at September 30, 2024, December 31, 2023, September 30, 2023 and December 31, 2022, respectively.

[11] Net of $(5) million, $3 million, $16 million and $9 million tax at September 30, 2024, June 30, 2024, September 30, 2023 and June 30, 2023, respectively.

[12] Net of $(5) million, $(2) million, $16 million and $13 million tax at September 30, 2024, December 31, 2023, September 30, 2023 and December 31, 2022, respectively.

[13] Net of $(2) million, $— million, $3 million and $1 million tax at September 30, 2024, June 30, 2024, September 30, 2023 and June 30, 2023, respectively.

[14] Net of $(2) million, $— million, $3 million and $2 million tax at September 30, 2024, December 31, 2023, September 30, 2023 and December 31, 2022, respectively.

[15] Net of $522 million, $522 million, $461 million and $453 million tax at September 30, 2024, June 30, 2024, September 30, 2023 and June 30, 2023, respectively.

[16] Net of $522 million, $456 million, $461 million and $445 million tax at September 30, 2024, December 31, 2023, September 30, 2023 and December 31, 2022, respectively.

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

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