Derivatives and Hedge Accounting Activities (Fair Value of Derivatives) (Detail) - USD ($) $ in Millions		Sep. 30, 2022	Dec. 31, 2021
Derivatives Fair Value [Line Items]
Derivative Asset, Current		$ 670	$ 122
Derivative Asset, Current		670	122	[1]
Derivative Asset, Noncurrent		1,799	491	[1]
Derivative Asset		2,469	613
Derivative Liabilities, Current		1,179	359
Derivative Liabilities, Current		1,179	359	[1]
Derivative Liabilities, Noncurrent		1,192	509	[1]
Derivative Liabilities		2,371	868
Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[2]	363	76	[3]
Derivative Asset, Noncurrent	[4]	598	224
Derivative Asset		961	300
Derivative Liabilities, Current	[2]	442	134	[3]
Derivative Liabilities, Noncurrent	[5]	475	336
Derivative Liabilities		917	470
Commodity Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		610	103
Derivative Asset, Noncurrent		260	179
Derivative Liabilities, Current		1,083	304
Derivative Liabilities, Noncurrent		426	165
Commodity Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		357	74
Derivative Asset, Noncurrent		2	72
Derivative Liabilities, Current		392	92
Derivative Liabilities, Noncurrent		111	41
Interest Rate Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		54	18
Derivative Asset, Noncurrent		1,539	305
Derivative Liabilities, Current		46	55
Derivative Liabilities, Noncurrent		429	344
Interest Rate Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current			1
Derivative Asset, Noncurrent		596	145
Derivative Liabilities, Current			42
Derivative Liabilities, Noncurrent		27	295
Foreign currency exchange rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current		6	1
Derivative Asset, Noncurrent			7
Derivative Liabilities, Current		50
Derivative Liabilities, Noncurrent		337
Foreign currency exchange rate | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		6	1
Derivative Asset, Noncurrent			7
Derivative Liabilities, Current		50
Derivative Liabilities, Noncurrent		337
Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Asset, Current		0	1
Derivative Asset, Noncurrent		596	145
Derivative Asset		596	146
Derivative Liabilities, Current		0	42
Derivative Liabilities, Noncurrent		27	295
Derivative Liabilities		27	337
Designated as Hedging Instrument | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		0	1
Derivative Asset, Noncurrent	[4]	596	145
Derivative Asset		596	146
Derivative Liabilities, Current		0	42
Derivative Liabilities, Noncurrent	[5]	27	295
Derivative Liabilities		27	337
Designated as Hedging Instrument | Commodity Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		0	0
Derivative Asset, Noncurrent		0	0
Derivative Liabilities, Current		0	0
Derivative Liabilities, Noncurrent		0	0
Designated as Hedging Instrument | Commodity Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		0	0
Derivative Asset, Noncurrent		0	0
Derivative Liabilities, Current		0	0
Derivative Liabilities, Noncurrent		0	0
Designated as Hedging Instrument | Interest Rate Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		0	1
Derivative Asset, Noncurrent		596	145
Derivative Liabilities, Current		0	42
Derivative Liabilities, Noncurrent		27	295
Designated as Hedging Instrument | Interest Rate Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current			1
Derivative Asset, Noncurrent		596	145
Derivative Liabilities, Current			42
Derivative Liabilities, Noncurrent		27	295
Designated as Hedging Instrument | Foreign currency exchange rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current		0	0
Derivative Asset, Noncurrent			0
Derivative Liabilities, Current		0
Derivative Liabilities, Noncurrent		0
Designated as Hedging Instrument | Foreign currency exchange rate | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		0	0
Derivative Asset, Noncurrent			0
Derivative Liabilities, Current		0
Derivative Liabilities, Noncurrent		0
Fair Value - Derivatives not under Hedge Accounting
Derivatives Fair Value [Line Items]
Derivative Asset, Current		670	121
Derivative Asset, Noncurrent		1,203	346
Derivative Asset		1,873	467
Derivative Liabilities, Current		1,179	317
Derivative Liabilities, Noncurrent		1,165	214
Derivative Liabilities		2,344	531
Fair Value - Derivatives not under Hedge Accounting | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		363	75
Derivative Asset, Noncurrent	[4]	2	79
Derivative Asset		365	154
Derivative Liabilities, Current		442	92
Derivative Liabilities, Noncurrent	[5]	448	41
Derivative Liabilities		890	133
Fair Value - Derivatives not under Hedge Accounting | Commodity Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		610	103
Derivative Asset, Noncurrent		260	179
Derivative Liabilities, Current		1,083	304
Derivative Liabilities, Noncurrent		426	165
Fair Value - Derivatives not under Hedge Accounting | Commodity Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		357	74
Derivative Asset, Noncurrent		2	72
Derivative Liabilities, Current		392	92
Derivative Liabilities, Noncurrent		111	41
Fair Value - Derivatives not under Hedge Accounting | Interest Rate Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		54	17
Derivative Asset, Noncurrent		943	160
Derivative Liabilities, Current		46	13
Derivative Liabilities, Noncurrent		402	49
Fair Value - Derivatives not under Hedge Accounting | Interest Rate Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current			0
Derivative Asset, Noncurrent		0	0
Derivative Liabilities, Current			0
Derivative Liabilities, Noncurrent		0	0
Fair Value - Derivatives not under Hedge Accounting | Foreign currency exchange rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current		6	1
Derivative Asset, Noncurrent			7
Derivative Liabilities, Current		50
Derivative Liabilities, Noncurrent		337
Fair Value - Derivatives not under Hedge Accounting | Foreign currency exchange rate | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		6	1
Derivative Asset, Noncurrent			$ 7
Derivative Liabilities, Current		50
Derivative Liabilities, Noncurrent		$ 337

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

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

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

[4] Noncurrent derivative assets are presented in other deferred charges and other assets in Virginia Power’s Consolidated Balance Sheets. 

[5] Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Virginia Power’s Consolidated Balance Sheets.