Derivatives and Hedge Accounting Activities (Fair Value of Derivatives) (Detail) - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[1]	$ 122	$ 67
Derivative Asset, Noncurrent	[2]	491	330
Derivative Asset		613	397
Derivative Liabilities, Current	[3]	359	415
Derivative Liabilities, Noncurrent	[4]	509	71
Derivative Liabilities		868	486
Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[5]	76	22
Derivative Asset, Noncurrent	[6]	224	159
Derivative Asset		300	181
Derivative liabilities	[7]	134	390
Derivative Liability, Noncurrent	[8]	336	15
Derivative Liabilities		470	405
Commodity
Derivatives Fair Value [Line Items]
Derivative Asset, Current		103	58
Derivative Asset, Noncurrent		179	109
Derivative Liabilities, Current		304	42
Derivative Liabilities, Noncurrent		165	13
Commodity | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		74	22
Derivative Asset, Noncurrent		72	93
Derivative liabilities		92	28
Derivative Liability, Noncurrent		41	1
Interest rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current		18	9
Derivative Asset, Noncurrent		305	221
Derivative Liabilities, Current		55	373
Derivative Liabilities, Noncurrent		344	58
Interest rate | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		1
Derivative Asset, Noncurrent		145	66
Derivative liabilities		42	362
Derivative Liability, Noncurrent		295	14
Foreign currency exchange rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current		1
Derivative Asset, Noncurrent		7
Foreign currency exchange rate | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		1
Derivative Asset, Noncurrent		7
Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[1]	1
Derivative Asset, Noncurrent	[2]	145	66
Derivative Asset		146	66
Derivative Liabilities, Current	[3]	42	363
Derivative Liabilities, Noncurrent	[4]	295	19
Derivative Liabilities		337	382
Designated as Hedging Instrument | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[5]	1
Derivative Asset, Noncurrent	[6]	145	66
Derivative Asset		146	66
Derivative liabilities		42	362
Derivative Liability, Noncurrent	[8]	295	14
Derivative Liabilities		337	376
Designated as Hedging Instrument | Interest rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current		1
Derivative Asset, Noncurrent		145	66
Derivative Liabilities, Current		42	363
Derivative Liabilities, Noncurrent		295	19
Designated as Hedging Instrument | Interest rate | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		1
Derivative Asset, Noncurrent		145	66
Derivative liabilities		42	362
Derivative Liability, Noncurrent		295	14
Fair Value - Derivatives not under Hedge Accounting
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[1]	121	67
Derivative Asset, Noncurrent	[2]	346	264
Derivative Asset		467	331
Derivative Liabilities, Current	[3]	317	52
Derivative Liabilities, Noncurrent	[4]	214	52
Derivative Liabilities		531	104
Fair Value - Derivatives not under Hedge Accounting | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current	[5]	75	22
Derivative Asset, Noncurrent	[6]	79	93
Derivative Asset		154	115
Derivative liabilities		92	28
Derivative Liability, Noncurrent	[8]	41	1
Derivative Liabilities		133	29
Fair Value - Derivatives not under Hedge Accounting | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset, Current		103	58
Derivative Asset, Noncurrent		179	109
Derivative Liabilities, Current		304	42
Derivative Liabilities, Noncurrent		165	13
Fair Value - Derivatives not under Hedge Accounting | Commodity | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset, Current		74	22
Derivative Asset, Noncurrent		72	93
Derivative liabilities		92	28
Derivative Liability, Noncurrent		41	1
Fair Value - Derivatives not under Hedge Accounting | Interest rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current		17	9
Derivative Asset, Noncurrent		160	155
Derivative Liabilities, Current		13	10
Derivative Liabilities, Noncurrent		49	$ 39
Fair Value - Derivatives not under Hedge Accounting | Foreign currency exchange rate
Derivatives Fair Value [Line Items]
Derivative Asset, Current		1
Derivative Asset, Noncurrent		7
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

[1] At December 31, 2021, all current derivative assets are presented in other current assets in Dominion Energy’s Consolidated Balance Sheets. At December 31, 2020, $63 million is included in other current assets and the remainder is recorded in current assets held for sale.

[2] At December 31, 2021, all noncurrent derivative assets are presented in other deferred charges and other assets in Dominion Energy’s Consolidated Balance Sheets. At December 31, 2020, $330 million is included in other deferred charges and other assets and the remainder is recorded in noncurrent assets held for sale.

[3] At December 31, 2021, all current derivative liabilities are presented in other current liabilities in Dominion Energy’s Consolidated Balance Sheets. At December 31, 2020, $412 million is included in other current liabilities and the remainder is recorded in current liabilities held for sale.

[4] At December 31, 2021, all noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion Energy’s Consolidated Balance Sheets. At December 31, 2020, $71 million is included in other deferred credits and other liabilities and the remainder is recorded in noncurrent liabilities held for sale.

[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 25 for amounts attributable to affiliates.

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