Derivatives and Hedge Accounting Activities (Fair Value of Derivatives) (Detail) - USD ($) $ in Millions		Mar. 31, 2022	Dec. 31, 2021
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[1]	$ 280	$ 122
Derivative Asset, Noncurrent	[2]	929	491
Derivative Asset		1,209	613
Derivative Liabilities, Current		727	359	[3]
Derivative Liabilities, Noncurrent	[4]	587	509
Derivative Liabilities		1,314	868
Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[5]	114	76
Derivative Asset, Noncurrent	[6]	290	224
Derivative Asset		404	300
Derivative Liabilities, Current	[7]	241	134	[8]
Derivative Liabilities, Noncurrent	[9]	267	336
Derivative Liabilities		508	470
Commodity Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		227	103
Derivative Asset, Noncurrent		214	179
Derivative Liabilities, Current		725	304
Derivative Liabilities, Noncurrent		223	165
Commodity Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		80	74
Derivative Asset, Noncurrent		24	72
Derivative Liabilities, Current		240	92
Derivative Liabilities, Noncurrent		64	41
Interest Rate Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		53	18
Derivative Asset, Noncurrent		715	305
Derivative Liabilities, Current		1	55
Derivative Liabilities, Noncurrent		361	344
Interest Rate Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		34	1
Derivative Asset, Noncurrent		266	145
Derivative Liabilities, Current			42
Derivative Liabilities, Noncurrent		200	295
Foreign currency exchange rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current			1
Derivative Asset, Noncurrent			7
Derivative Liabilities, Current		1
Derivative Liabilities, Noncurrent		3
Foreign currency exchange rate | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current			1
Derivative Asset, Noncurrent			7
Derivative Liabilities, Current		1
Derivative Liabilities, Noncurrent		3
Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[1]	40	1
Derivative Asset, Noncurrent	[2]	266	145
Derivative Asset		306	146
Derivative Liabilities, Current		0	42
Derivative Liabilities, Noncurrent	[4]	200	295
Derivative Liabilities		200	337
Designated as Hedging Instrument | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[5]	34	1
Derivative Asset, Noncurrent	[6]	266	145
Derivative Asset		300	146
Derivative Liabilities, Current		0	42
Derivative Liabilities, Noncurrent	[9]	200	295
Derivative Liabilities		200	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		40	1
Derivative Asset, Noncurrent		266	145
Derivative Liabilities, Current		0	42
Derivative Liabilities, Noncurrent		200	295
Designated as Hedging Instrument | Interest Rate Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		34	1
Derivative Asset, Noncurrent		266	145
Derivative Liabilities, Current			42
Derivative Liabilities, Noncurrent		200	295
Designated as Hedging Instrument | Foreign currency exchange rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current			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
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	[1]	240	121
Derivative Asset, Noncurrent	[2]	663	346
Derivative Asset		903	467
Derivative Liabilities, Current		727	317
Derivative Liabilities, Noncurrent	[4]	387	214
Derivative Liabilities		1,114	531
Fair Value - Derivatives not under Hedge Accounting | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[5]	80	75
Derivative Asset, Noncurrent	[6]	24	79
Derivative Asset		104	154
Derivative Liabilities, Current		241	92
Derivative Liabilities, Noncurrent	[9]	67	41
Derivative Liabilities		308	133
Fair Value - Derivatives not under Hedge Accounting | Commodity Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		227	103
Derivative Asset, Noncurrent		214	179
Derivative Liabilities, Current		725	304
Derivative Liabilities, Noncurrent		223	165
Fair Value - Derivatives not under Hedge Accounting | Commodity Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		80	74
Derivative Asset, Noncurrent		24	72
Derivative Liabilities, Current		240	92
Derivative Liabilities, Noncurrent		64	41
Fair Value - Derivatives not under Hedge Accounting | Interest Rate Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		13	17
Derivative Asset, Noncurrent		449	160
Derivative Liabilities, Current		1	13
Derivative Liabilities, Noncurrent		161	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	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			1
Derivative Asset, Noncurrent			7
Derivative Liabilities, Current		1
Derivative Liabilities, Noncurrent		3
Fair Value - Derivatives not under Hedge Accounting | Foreign currency exchange rate | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current			1
Derivative Asset, Noncurrent			$ 7
Derivative Liabilities, Current		1
Derivative Liabilities, Noncurrent		$ 3

[1] Current derivative assets are presented in other current assets in Dominion Energy’s Consolidated Balance Sheets.

[2] Noncurrent derivative assets are presented in other deferred charges and other assets in Dominion Energy’s Consolidated Balance Sheets.

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

[4] Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion Energy’s Consolidated Balance Sheets

[5] Current derivative assets are presented in other current assets in Virginia Power’s Consolidated Balance Sheets.

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

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

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

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