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
		Mar. 31, 2022		Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]	$ 27,308
Interest and related charges		(174)		$ (53)
Income tax expense		(236)		(212)
Net Income From Continuing Operations		692		980
Total other comprehensive income		22		46
Ending balance		27,520
Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		15,980	[2]	14,557
Interest and related charges	[3]	(148)		(136)
Income before income tax expense		418		444
Income tax expense		(61)		(70)
Total other comprehensive income		12		29
Ending balance		16,348		14,811
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 From Continuing Operations				1
Interest Rate
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(358)		(418)
Other comprehensive income before reclassifications: gains (losses)		25		39
Total other comprehensive income		35		51
Ending balance		(323)		(367)
Interest Rate | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges		14		16
Income before income tax expense		14		16
Income tax expense		(4)		(4)
Net Income From Continuing Operations		10		12
Total Derivative-Hedging Activities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[4]	(358)		(419)
Other comprehensive income before reclassifications: gains (losses)	[4]	25		39
Total other comprehensive income	[4]	35		52
Ending balance	[4]	(323)		(367)
Total Derivative-Hedging Activities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[5]	(45)		(60)
Other comprehensive income before reclassifications: gains (losses)	[5]	19		32
Total other comprehensive income	[5]	20		33
Ending balance	[5]	(25)		(27)
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
Income before income tax expense	[4]	14		17
Income tax expense	[4]	(4)		(4)
Net Income From Continuing Operations	[4]	10		13
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 From Continuing Operations	[5]	1		1
Investment Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[6]	37		62
Other comprehensive income before reclassifications: gains (losses)	[6]	(62)		(31)
Total other comprehensive income	[6]	(59)		(30)
Ending balance	[6]	(22)		32
Investment Securities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[7]	4		8
Other comprehensive income before reclassifications: gains (losses)	[7]	(7)		(5)
Total other comprehensive income	[7]	(8)		(4)
Ending balance	[7]	(4)		4
Investment Securities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income	[6]	4		1
Income before income tax expense	[6]	4		1
Income tax expense	[6]	(1)
Net Income From Continuing Operations	[6]	3		1
Investment Securities | Reclassification out of Accumulated Other Comprehensive Income | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income	[7]	(1)		1
Income before income tax expense	[7]	(1)		1
Net Income From Continuing Operations	[7]	(1)		1
Pension and Other Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[8]	(1,133)		(1,359)
Other comprehensive income before reclassifications: gains (losses)	[8]	28		6
Total other comprehensive income	[8]	45		24
Ending balance	[8]	(1,088)		(1,335)
Pension and Other Postretirement Benefit Costs | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income	[8]	23		25
Income before income tax expense	[8]	23		25
Income tax expense	[8]	(6)		(7)
Net Income From Continuing Operations	[8]	17		18
Equity Method Investees
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[9]	(4)		(1)
Other comprehensive income before reclassifications: gains (losses)	[9]	1
Total other comprehensive income	[9]	1
Ending balance	[9]	(3)		(1)
AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,458)		(1,717)
Other comprehensive income before reclassifications: gains (losses)		(8)		14
Total other comprehensive income		22		46
Ending balance		(1,436)		(1,671)
AOCI | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(41)		(52)
Other comprehensive income before reclassifications: gains (losses)		12		27
Total other comprehensive income		12		29
Ending balance		(29)		(23)
AOCI | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Purchased Gas				1
Interest and related charges		14		16
Other income		27		26
Income before income tax expense		41		43
Income tax expense		(11)		(11)
Net Income From Continuing Operations		30		32
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		(1)		1
Income before income tax expense				2
Net Income From Continuing Operations				2
Interest Rate | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(45)		(60)
Other comprehensive income before reclassifications: gains (losses)		19		32
Total other comprehensive income		20		33
Ending balance		(25)		(27)
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 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 $107 million, $119 million, $123 million and $141 million tax at March 31, 2022, December 31, 2021, March 31, 2021 and December 31, 2020, respectively.

[5] Net of $9 million, $16 million, $10 million and $21 million tax at March 31, 2022, December 31, 2021, March 31, 2021 and December 31, 2020, respectively.

[6] Net of $8 million, $(10) million, $(11) million and $(21) million tax at March 31, 2022, December 31, 2021, March 31, 2021 and December 31, 2020, respectively.

[7] Net of $1 million, $(2) million, $(2) million and $(3) million tax at March 31, 2022, December 31, 2021, March 31, 2021 and December 31, 2020, respectively.

[8] Net of $380 million, $396 million, $468 million and $478 million tax at March 31, 2022, December 31, 2021, March 31, 2021 and December 31, 2020, respectively.

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