Derivatives and Hedge Accounting Activities (Fair Value of Derivatives) (Detail) - USD ($) $ in Millions		Dec. 31, 2022	Dec. 31, 2021
Derivatives Fair Value [Line Items]
Derivative Asset, Current		$ 1,137	$ 122
Derivative Asset, Noncurrent	[1]	1,039	491
Total derivative assets		2,176	613
Derivative liabilities		778	359
Derivative Liability, Noncurrent	[2]	626	509
Total derivative liabilities		1,404	868
Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[3]	765	76
Derivative Asset, Noncurrent	[1]	117	224
Total derivative assets		882	300
Derivative liabilities	[4]	298	134
Derivative Liability, Noncurrent	[2]	158	336
Total derivative liabilities		456	470
Commodity Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		532	103
Derivative Asset, Noncurrent		237	179
Derivative liabilities		700	304
Derivative Liability, Noncurrent		226	165
Commodity Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		264	74
Derivative Asset, Noncurrent		4	72
Derivative liabilities		290	92
Derivative Liability, Noncurrent		58	41
Interest Rate Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		605	18
Derivative Asset, Noncurrent		802	305
Derivative liabilities		70	55
Derivative Liability, Noncurrent		307	344
Interest Rate Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		501	1
Derivative Asset, Noncurrent		113	145
Derivative liabilities		0	42
Derivative Liability, Noncurrent		7	295
Foreign currency exchange rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current			1
Derivative Asset, Noncurrent			7
Derivative liabilities		8
Derivative Liability, Noncurrent		93
Foreign currency exchange rate | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current			1
Derivative Asset, Noncurrent			7
Derivative liabilities		8
Derivative Liability, Noncurrent		93
Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Asset, Current		501	1
Derivative Asset, Noncurrent	[1]	113	145
Total derivative assets		614	146
Derivative liabilities		0	42
Derivative Liability, Noncurrent	[2]	7	295
Total derivative liabilities		7	337
Designated as Hedging Instrument | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		501	1
Derivative Asset, Noncurrent	[1]	113	145
Total derivative assets		614	146
Derivative liabilities		0	42
Derivative Liability, Noncurrent	[2]	7	295
Total derivative liabilities		7	337
Designated as Hedging Instrument | Commodity Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		0	0
Derivative Asset, Noncurrent		0	0
Derivative liabilities		0	0
Derivative Liability, 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		0	0
Derivative Liability, Noncurrent		0	0
Designated as Hedging Instrument | Interest Rate Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		501	1
Derivative Asset, Noncurrent		113	145
Derivative liabilities		0	42
Derivative Liability, Noncurrent		7	295
Designated as Hedging Instrument | Interest Rate Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		501	1
Derivative Asset, Noncurrent		113	145
Derivative liabilities		0	42
Derivative Liability, Noncurrent		7	295
Designated as Hedging Instrument | Foreign currency exchange rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current			0
Derivative Asset, Noncurrent			0
Derivative liabilities		0
Derivative Liability, 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		0
Derivative Liability, Noncurrent		0
Fair Value - Derivatives not under Hedge Accounting
Derivatives Fair Value [Line Items]
Derivative Asset, Current		636	121
Derivative Asset, Noncurrent	[1]	926	346
Total derivative assets		1,562	467
Derivative liabilities		778	317
Derivative Liability, Noncurrent	[2]	619	214
Total derivative liabilities		1,397	531
Fair Value - Derivatives not under Hedge Accounting | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		264	75
Derivative Asset, Noncurrent	[1]	4	79
Total derivative assets		268	154
Derivative liabilities		298	92
Derivative Liability, Noncurrent	[2]	151	41
Total derivative liabilities		449	133
Fair Value - Derivatives not under Hedge Accounting | Commodity Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		532	103
Derivative Asset, Noncurrent		237	179
Derivative liabilities		700	304
Derivative Liability, Noncurrent		226	165
Fair Value - Derivatives not under Hedge Accounting | Commodity Contract | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		264	74
Derivative Asset, Noncurrent		4	72
Derivative liabilities		290	92
Derivative Liability, Noncurrent		58	41
Fair Value - Derivatives not under Hedge Accounting | Interest Rate Contract
Derivatives Fair Value [Line Items]
Derivative Asset, Current		104	17
Derivative Asset, Noncurrent		689	160
Derivative liabilities		70	13
Derivative Liability, Noncurrent		300	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		0	0
Derivative Liability, 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		8
Derivative Liability, Noncurrent		93
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		8
Derivative Liability, Noncurrent		$ 93

[1] Virginia Power’s noncurrent derivative assets are presented in other deferred charges and other assets in its Consolidated Balance Sheets.

[2] Virginia Power’s noncurrent derivative liabilities are presented in other deferred credits and other liabilities in its Consolidated Balance Sheets.

[3] See Note 25 for amounts attributable to affiliates.

[4] See Note 25 for amounts attributable to affiliates.