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, 2022	Jun. 30, 2021	Jun. 30, 2022		Jun. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]			$ 27,308
Interest and related charges		$ (47)	$ (518)	(221)		$ (571)
Other income (expense)		(287)	312	(241)		599
Income tax expense (benefit)		117	47	(119)		(165)
Net Income (Loss) From Continuing Operations		(452)	269	240		1,249
Total other comprehensive income		40	31	62		77
Ending balance		28,297		28,297
Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		16,348	14,811	15,980	[2]	14,557
Interest and related charges	[3]	(145)	(128)	(293)		(264)
Other income (expense)		(44)	40	(40)		72
Income before income tax expense		47	483	465		927
Income tax expense (benefit)			(69)	(61)		(139)
Total other comprehensive income		22	(10)	34		19
Ending balance		16,418	15,064	16,418		15,064
Commodity
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance						(1)
Total other comprehensive income						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 (Loss) From Continuing Operations						1
Interest Rate
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(323)	(367)	(358)		(418)
Other comprehensive income before reclassifications: gains (losses)		29	(16)	54		23
Total other comprehensive income		40	(4)	75		47
Ending balance		(283)	(371)	(283)		(371)
Interest Rate | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges		14	16	28		32
Income before income tax expense		14	16	28		32
Income tax expense (benefit)		(3)	(4)	(7)		(8)
Net Income (Loss) From Continuing Operations		11	12	21		24
Total Derivative-Hedging Activities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[4]	(323)	(367)	(358)		(419)
Other comprehensive income before reclassifications: gains (losses)	[4]	29	(16)	54		23
Total other comprehensive income	[4]	40	(4)	75		48
Ending balance	[4]	(283)	(371)	(283)		(371)
Total Derivative-Hedging Activities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[5]	(25)	(27)	(45)		(60)
Other comprehensive income before reclassifications: gains (losses)	[5]	25	(12)	44		20
Total other comprehensive income	[5]	25	(12)	45		21
Ending balance	[5]		(39)			(39)
Total Derivative-Hedging Activities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Purchased Gas	[4]					1
Interest and related charges	[4]	14	16	28		32
Income before income tax expense	[4]	14	16	28		33
Income tax expense (benefit)	[4]	(3)	(4)	(7)		(8)
Net Income (Loss) From Continuing Operations	[4]	11	12	21		25
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	[5]			1		1
Income before income tax expense	[5]			1		1
Net Income (Loss) From Continuing Operations	[5]			1		1
Investment Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[6]	(22)	32	37		62
Other comprehensive income before reclassifications: gains (losses)	[6]	(27)	12	(89)		(19)
Total other comprehensive income	[6]	(18)	9	(77)		(21)
Ending balance	[6]	(40)	41	(40)		41
Investment Securities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[7]	(4)	4	4		8
Other comprehensive income before reclassifications: gains (losses)	[7]	(3)	3	(10)		(2)
Total other comprehensive income	[7]	(3)	2	(11)		(2)
Ending balance	[7]	(7)	6	(7)		6
Investment Securities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)	[6]	12	(4)	16		(3)
Income before income tax expense	[6]	12	(4)	16		(3)
Income tax expense (benefit)	[6]	(3)	1	(4)		1
Net Income (Loss) From Continuing Operations	[6]	9	(3)	12		(2)
Investment Securities | Reclassification out of Accumulated Other Comprehensive Income | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)	[7]		(1)	(1)
Income before income tax expense	[7]		(1)	(1)
Net Income (Loss) From Continuing Operations	[7]		(1)	(1)
Pension and Other Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[8]	(1,088)	(1,335)	(1,133)		(1,359)
Other comprehensive income before reclassifications: gains (losses)	[8]	2		30		6
Total other comprehensive income	[8]	18	26	63		50
Ending balance	[8]	(1,070)	(1,309)	(1,070)		(1,309)
Pension and Other Postretirement Benefit Costs | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense)	[8]	22	35	45		60
Income before income tax expense	[8]	22	35	45		60
Income tax expense (benefit)	[8]	(6)	(9)	(12)		(16)
Net Income (Loss) From Continuing Operations	[8]	16	26	33		44
Equity Method Investees
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[9]	(3)	(1)	(4)		(1)
Other comprehensive income before reclassifications: gains (losses)	[9]			1
Total other comprehensive income	[9]	0		1
Ending balance	[9]	(3)	(1)	(3)		(1)
AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,436)	(1,671)	(1,458)		(1,717)
Other comprehensive income before reclassifications: gains (losses)		4	(4)	(4)		10
Total other comprehensive income		40	31	62		77
Ending balance		(1,396)	(1,640)	(1,396)		(1,640)
AOCI | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(29)	(23)	(41)		(52)
Other comprehensive income before reclassifications: gains (losses)		22	(9)	34		18
Total other comprehensive income		22	(10)	34		19
Ending balance		(7)	(33)	(7)		(33)
AOCI | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Purchased Gas						1
Interest and related charges		14	16	28		32
Other income (expense)		34	31	61		57
Income before income tax expense		48	47	89		90
Income tax expense (benefit)		(12)	(12)	(23)		(23)
Net Income (Loss) From Continuing Operations		36	35	66		67
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
Other income (expense)			(1)	(1)
Income before income tax expense			(1)			1
Net Income (Loss) From Continuing Operations			(1)			1
Interest Rate | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(25)	(27)	(45)		(60)
Other comprehensive income before reclassifications: gains (losses)		25	(12)	44		20
Total other comprehensive income		$ 25	(12)	45		21
Ending balance			$ (39)			(39)
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
Income before income tax expense				1		1
Net Income (Loss) 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 $94 million,$119 million, $125 million and $141 million tax at June 30, 2022, December 31, 2021, June 30, 2021 and December 31, 2020, respectively.

[5] Net of $— million, $16 million, $14 million and $21 million tax at June 30, 2022, December 31, 2021, June 30, 2021 and December 31, 2020, respectively.

[6] Net of $14 million, $(10) million, $(12) million and $(21) million tax at June 30, 2022, December 31, 2021, June 30, 2021 and December 31, 2020, respectively.

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

[8] Net of $376 million, $396 million, $455 million, and $478 million tax at June 30, 2022, December 31, 2021, June 30, 2021 and December 31, 2020, respectively.

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