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, 2022		Sep. 30, 2021		Sep. 30, 2022		Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]					$ 27,308
Interest and related charges		$ (329)		$ (407)		(550)		$ (978)
Other income (expense)		70		133		(171)		732
Income tax expense (benefit)		(124)		(35)		(243)		(200)
Net Income From Continuing Operations		781		601		1,021		1,850
Total other comprehensive income (loss)		22		24		84		101
Ending balance		28,573				28,573
Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		16,418		15,064		15,980	[2]	14,557
Interest and related charges	[3]	(168)		(136)		(461)		(400)
Other income (expense)		3		21		(37)		93
Income before income tax expense		637		662		1,102		1,589
Income tax expense (benefit)		(66)		(106)		(127)		(245)
Total other comprehensive income (loss)		9		(3)		43		16
Ending balance		16,998		15,617		16,998		15,617
Commodity
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance								(1)
Total other comprehensive income (loss)								1
Commodity | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Purchased Gas								1
Income before income tax expense								1
Net Income From Continuing Operations								1
Interest Rate
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(283)		(371)		(358)		(418)
Other comprehensive income before reclassifications: gains (losses)		10		(2)		64		21
Total other comprehensive income (loss)		22		8		97		55
Ending balance		(261)		(363)		(261)		(363)
Interest Rate | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges		16		14		44		46
Income before income tax expense		16		14		44		46
Income tax expense (benefit)		(4)		(4)		(11)		(12)
Net Income From Continuing Operations		12		10		33		34
Total Derivative-Hedging Activities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(283)	[4]	(371)	[4]	(358)	[5]	(419)	[5]
Other comprehensive income before reclassifications: gains (losses)		10	[4]	(2)	[4]	64	[5]	21	[5]
Total other comprehensive income (loss)		22	[4]	8	[4]	97	[5]	56	[5]
Ending balance	[4],[5]	(261)		(363)		(261)		(363)
Total Derivative-Hedging Activities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance				(39)	[6]	(45)	[7]	(60)	[7]
Other comprehensive income before reclassifications: gains (losses)		13	[6]	(2)	[6]	57	[7]	18	[7]
Total other comprehensive income (loss)		13	[6]	(2)	[6]	58	[7]	19	[7]
Ending balance	[6],[7]	13		(41)		13		(41)
Total Derivative-Hedging Activities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Purchased Gas	[5]							1
Interest and related charges		16	[4]	14	[4]	44	[5]	46	[5]
Income before income tax expense		16	[4]	14	[4]	44	[5]	47	[5]
Income tax expense (benefit)		(4)	[4]	(4)	[4]	(11)	[5]	(12)	[5]
Net Income From Continuing Operations		12	[4]	10	[4]	33	[5]	35	[5]
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		1	[6]	1	[6]	2	[7]	2	[7]
Income before income tax expense		1	[6]	1	[6]	2	[7]	2	[7]
Income tax expense (benefit)		(1)	[6]	(1)	[6]	(1)	[7]	(1)	[7]
Net Income From Continuing Operations	[7]					1		1
Investment Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(40)	[8]	41	[8]	37	[9]	62	[9]
Other comprehensive income before reclassifications: gains (losses)		(27)	[8]	4	[8]	(116)	[9]	(15)	[9]
Total other comprehensive income (loss)		(26)	[8]	1	[8]	(103)	[9]	(20)	[9]
Ending balance	[8],[9]	(66)		42		(66)		42
Investment Securities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(7)	[10]	6	[10]	4	[11]	8	[11]
Other comprehensive income before reclassifications: gains (losses)		(4)	[10]	0	[10]	(14)	[11]	(2)	[11]
Total other comprehensive income (loss)		(4)	[10]	(1)	[10]	(15)	[11]	(3)	[11]
Ending balance	[10],[11]	(11)		5		(11)		5
Investment Securities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)		2	[8]	(4)	[8]	18	[9]	(7)	[9]
Income before income tax expense		2	[8]	(4)	[8]	18	[9]	(7)	[9]
Income tax expense (benefit)		(1)	[8]	1	[8]	(5)	[9]	2	[9]
Net Income From Continuing Operations		1	[8]	(3)	[8]	13	[9]	(5)	[9]
Investment Securities | Reclassification out of Accumulated Other Comprehensive Income | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)				(1)	[10]	(1)	[11]	(1)	[11]
Income before income tax expense				(1)	[10]	(1)	[11]	(1)	[11]
Net Income From Continuing Operations				(1)	[10]	(1)	[11]	(1)	[11]
Pension and Other Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,070)	[12]	(1,309)	[12]	(1,133)	[13]	(1,359)	[13]
Other comprehensive income before reclassifications: gains (losses)				(1)	[12]	30	[13]	5	[13]
Total other comprehensive income (loss)		26	[12]	18	[12]	89	[13]	68	[13]
Ending balance	[12],[13]	(1,044)		(1,291)		(1,044)		(1,291)
Pension and Other Postretirement Benefit Costs | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)		35	[12]	25	[12]	80	[13]	85	[13]
Income before income tax expense		35	[12]	25	[12]	80	[13]	85	[13]
Income tax expense (benefit)		(9)	[12]	(6)	[12]	(21)	[13]	(22)	[13]
Net Income From Continuing Operations		26	[12]	19	[12]	59	[13]	63	[13]
Equity Method Investees
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(3)	[14]	(1)	[14]	(4)	[15]	(1)	[15]
Other comprehensive income before reclassifications: gains (losses)				(3)	[14]	1	[15]	(3)	[15]
Total other comprehensive income (loss)		0	[14]	(3)	[14]	1	[15]	(3)	[15]
Ending balance	[14],[15]	(3)		(4)		(3)		(4)
AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,396)		(1,640)		(1,458)		(1,717)
Other comprehensive income before reclassifications: gains (losses)		(17)		(2)		(21)		8
Total other comprehensive income (loss)		22		24		84		101
Ending balance		(1,374)		(1,616)		(1,374)		(1,616)
AOCI | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(7)		(33)		(41)		(52)
Other comprehensive income before reclassifications: gains (losses)		9		(2)		43		16
Total other comprehensive income (loss)		9		(3)		43		16
Ending balance		2		(36)		2		(36)
AOCI | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Purchased Gas								1
Interest and related charges		16		14		44		46
Other income (expense)		37		21		98		78
Income before income tax expense		53		35		142		125
Income tax expense (benefit)		(14)		(9)		(37)		(32)
Net Income From Continuing Operations		39		26		105		93
AOCI | Reclassification out of Accumulated Other Comprehensive Income | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges		1		1		2		2
Other income (expense)				(1)		(1)		(1)
Income before income tax expense		1				1		1
Income tax expense (benefit)		(1)		(1)		(1)		(1)
Net Income From Continuing Operations				(1)
Interest Rate | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance				(39)		(45)		(60)
Other comprehensive income before reclassifications: gains (losses)		13		(2)		57		18
Total other comprehensive income (loss)		13		(2)		58		19
Ending balance		13		(41)		13		(41)
Interest Rate | Reclassification out of Accumulated Other Comprehensive Income | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges		1		1		2		2
Income before income tax expense		1		1		2		2
Income tax expense (benefit)		$ (1)		$ (1)		(1)		(1)
Net Income From Continuing Operations						$ 1		$ 1

[1] Dominion Energy’s Consolidated Balance Sheet at December 31, 2021 has been derived from the audited Consolidated Balance Sheet at that date.

[2] Virginia Power’s Consolidated Balance Sheet at December 31, 2021 has been derived from the audited Consolidated Balance Sheet at that date.

[3] See Note 19 for amounts attributable to affiliates.

[4] Net of $87 million, $94 million, $121 million and $125 million tax at September 30, 2022, June 30, 2022, September 30, 2021 and June 30, 2021, respectively.

[5] Net of $87 million, $119 million, $121 million and $141 million tax at September 30, 2022, December 31, 2021, September 30, 2021 and December 31, 2020, respectively.

[6] Net of $(4) million, $— million, $14 million and $14 million tax at September 30, 2022, June 30, 2022, September 30, 2021 and June 30, 2021, respectively

[7] Net of $(4) million, $16 million, $14 million and $21 million tax at September 30, 2022, December 31, 2021, September 30, 2021 and December 31, 2020, respectively.

[8] Net of $23 million, $14 million, $(11) million and $(12) million tax at September 30, 2022, June 30, 2022, September 30, 2021 and June 30, 2021, respectively.

[9] Net of $23 million, $(10) million, $(11) million and $(21) million tax at September 30, 2022, December 31, 2021, September 30, 2021 and December 31, 2020, respectively.

[10] Net of $4 million, $3 million, $(2) million and $(2) million tax at September 30, 2022, June 30, 2022, September 30, 2021 and June 30, 2021, respectively.

[11] Net of $4 million, $(2) million, $(2) million and $(3) million tax at September 30, 2022, December 31, 2021, September 30, 2021 and December 31, 2020, respectively.

[12] Net of $367 million, $376 million, $448 million and $455 million tax at September 30, 2022, June 30, 2022, September 30, 2021 and June 30, 2021, respectively.

[13] Net of $367 million, $396 million, $448 million, and $478 million tax at September 30, 2022, December 31, 2021, September 30, 2021 and December 31, 2020, respectively.

[14] Net of $1 million, $1 million, $1 million and $— million tax at September 30, 2022, June 30, 2022, September 30, 2021 and June 30, 2021, respectively.

[15] Net of $1 million, $1 million, $1 million and $— tax at September 30, 2022, December 31, 2021, September 30, 2021 and December 31, 2020, respectively.