Operating Revenue (Schedule of Operating Revenue) (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		$ 3,470	$ 3,746	$ 7,793	$ 7,376
Other revenues	[1]	115	224	288	452
Total operating revenue		3,585	3,970	8,081	7,828
Regulated Electric Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		1,091	1,094	2,249	1,740
Regulated Electric Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		728	889	1,526	1,385
Regulated Electric Sales | Industrial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		176	217	358	247
Regulated Electric Sales | Government and Other Retail
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		193	214	412	414
Regulated Electric Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		29	41	62	89
Nonregulated Electric Sales
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		177	175	409	491
Regulated Gas Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		182	177	730	779
Regulated Gas Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		63	73	254	264
Regulated Gas Sales | Other
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		16	25	44	63
Nonregulated Gas Sales
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		33	71	116	318
Regulated Gas Transportation and Storage | FERC-regulated
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		247	247	528	524
Regulated Gas Transportation and Storage | State-regulated
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		182	166	414	379
Nonregulated gas transportation and storage
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		176	174	351	348
Other Regulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2]	98	82	173	126
Other Nonregulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2],[3]	79	101	167	209
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		1,765	1,914	3,674	3,866
Other revenues	[1],[3]	40	24	61	37
Total operating revenue		1,805	1,938	3,735	3,903
Virginia Electric and Power Company | Regulated Electric Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		818	808	1,714	1,731
Virginia Electric and Power Company | Regulated Electric Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		546	681	1,160	1,317
Virginia Electric and Power Company | Regulated Electric Sales | Industrial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		89	118	186	230
Virginia Electric and Power Company | Regulated Electric Sales | Government and Other Retail
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		177	197	380	401
Virginia Electric and Power Company | Regulated Electric Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		21	29	45	66
Virginia Electric and Power Company | Other Regulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		94	62	156	88
Virginia Electric and Power Company | Other Nonregulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2],[3]	20	19	33	33
Dominion Energy Gas Holdings, LLC
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		509	529	1,064	1,094
Other revenues	[3]	1	1	2	2
Total operating revenue		510	530	1,066	1,096
Dominion Energy Gas Holdings, LLC | Regulated Gas Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		0	0	2	2
Dominion Energy Gas Holdings, LLC | Regulated Gas Transportation and Storage
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[3]	302	306	646	646
Dominion Energy Gas Holdings, LLC | Nonregulated gas transportation and storage
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		175	173	350	348
Dominion Energy Gas Holdings, LLC | Other Regulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2]	2	3	3	6
Dominion Energy Gas Holdings, LLC | Other Nonregulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2],[3]	1	1	2	1
Dominion Energy Gas Holdings, LLC | Nonregulated Gas Sale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[3]	0	1	1	3
Dominion Energy Gas Holdings, LLC | Management Service
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[3]	$ 29	$ 45	$ 60	$ 88

[1] Amounts above include alternative revenue of $39 million and $21 million at Dominion Energy and $34 million and $18 million at Virginia Power for the three months ended June 30, 2020 and 2019, respectively, and $75 million and $35 million at Dominion Energy and $51 million and $26 million at Virginia Power for the six months ended June 30, 2020 and 2019, respectively.

[2] Amounts above include sales which are considered to be goods transferred at a point in time. Such amounts included $19 million and $— million for the three months ended June 30, 2020, $42 million and $2 million for the three months ended June 30, 2019, $58 million and $1 million for the six months ended June 30, 2020 and $93 and $3 million for the six months ended June 30, 2019, primarily consisting of NGL sales at Dominion Energy and Dominion Energy Gas, respectively. Additionally, amounts above include sales of renewable energy credits. Such amounts included $7 million and $5 million for the three months ended June 30, 2020, $4 million and $2 million for the three months ended June 30, 2019, $11 million and $8 million for the six months ended June 30, 2020 and $7 million and $3 million for the six months ended June 30, 2019, at Dominion Energy and Virginia Power, respectively.

[3] See Notes 10 and 19 for amounts attributable to related parties and affiliates.