Operating Revenue (Schedule of Operating Revenue Recognition from Contracts with Customers) (Detail) - Adjustments for New Accounting Pronouncement - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Public Utilities General Disclosures [Line Items]
Operating revenue		$ 15,764	$ 12,895
Operating revenue		16,572	13,366
Other
Public Utilities General Disclosures [Line Items]
Operating revenue		4
Regulated Electric Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue		4,325	3,413
Regulated Electric Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue		3,219	2,503
Regulated Electric Sales | Industrial
Public Utilities General Disclosures [Line Items]
Operating revenue		683	490
Regulated Electric Sales | Government and Other Retail
Public Utilities General Disclosures [Line Items]
Operating revenue		873	854
Regulated Electric Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue		176	137
Nonregulated Electric Sales
Public Utilities General Disclosures [Line Items]
Operating revenue		926	1,294
Other
Public Utilities General Disclosures [Line Items]
Operating revenue	[1],[2]	808	471
Regulated Gas Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue		1,343	818
Regulated Gas Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue		457	221
Regulated Gas Sales | Other
Public Utilities General Disclosures [Line Items]
Operating revenue		117	36
Nonregulated Gas Sales
Public Utilities General Disclosures [Line Items]
Operating revenue		496	214
Regulated Gas Transportation and Storage | FERC-regulated
Public Utilities General Disclosures [Line Items]
Operating revenue		1,057	1,091
Regulated Gas Transportation and Storage | State-regulated
Public Utilities General Disclosures [Line Items]
Operating revenue		742	640
Nonregulated Gas Transportation And Storage
Public Utilities General Disclosures [Line Items]
Operating revenue		676	442
Other Regulated Revenue
Public Utilities General Disclosures [Line Items]
Operating revenue		259	179
Other Nonregulated Revenue
Public Utilities General Disclosures [Line Items]
Operating revenue	[1],[3]	415	563
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Operating revenue		8,036	7,584
Operating revenue		8,108	7,619
Virginia Electric and Power Company | Regulated Electric Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue		3,657	3,413
Virginia Electric and Power Company | Regulated Electric Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue		2,712	2,503
Virginia Electric and Power Company | Regulated Electric Sales | Industrial
Public Utilities General Disclosures [Line Items]
Operating revenue		455	490
Virginia Electric and Power Company | Regulated Electric Sales | Government and Other Retail
Public Utilities General Disclosures [Line Items]
Operating revenue		823	854
Virginia Electric and Power Company | Regulated Electric Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue		128	137
Virginia Electric and Power Company | Other
Public Utilities General Disclosures [Line Items]
Operating revenue	[2],[3]	72	35
Virginia Electric and Power Company | Other Regulated Revenue
Public Utilities General Disclosures [Line Items]
Operating revenue		190	132
Virginia Electric and Power Company | Other Nonregulated Revenue
Public Utilities General Disclosures [Line Items]
Operating revenue	[1],[3]	71	55
Dominion Energy Gas Holdings, LLC
Public Utilities General Disclosures [Line Items]
Operating revenue		2,165	2,002
Operating revenue		2,169	1,996
Dominion Energy Gas Holdings, LLC | Other
Public Utilities General Disclosures [Line Items]
Operating revenue			(6)
Dominion Energy Gas Holdings, LLC | Regulated Gas Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue		9	25
Dominion Energy Gas Holdings, LLC | Nonregulated Gas Sales
Public Utilities General Disclosures [Line Items]
Operating revenue	[3]	6	7
Dominion Energy Gas Holdings, LLC | Regulated Gas Transportation and Storage
Public Utilities General Disclosures [Line Items]
Operating revenue		1,300	1,249
Dominion Energy Gas Holdings, LLC | Nonregulated Gas Transportation And Storage
Public Utilities General Disclosures [Line Items]
Operating revenue		676	442
Dominion Energy Gas Holdings, LLC | Management Service Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue	[3]	162	257
Dominion Energy Gas Holdings, LLC | Other Regulated Revenue
Public Utilities General Disclosures [Line Items]
Operating revenue	[1],[3]	7	19
Dominion Energy Gas Holdings, LLC | Other Nonregulated Revenue
Public Utilities General Disclosures [Line Items]
Operating revenue	[1],[3]	$ 5	$ 3

[1] Amounts above include sales which are considered to be goods transferred at a point in time. For the years ended December 31, 2019 and 2018, such amounts included $171 million and $241 million, respectively, at Dominion Energy and $5 million and $10 million, respectively, at Dominion Energy Gas, primarily consisting of NGL sales. Additionally, amounts above include sales of renewable energy credits. For the years ended December 31, 2019 and 2018, such sales were $24 million and $ 17 million, respectively, at Dominion Energy and $17 million and $11 million, respectively, at Virginia Power.

[2] Includes alternative revenue of $66 million and $52 million for the year ended December 31, 2019 at Dominion Energy and Virginia Power, respectively, and $15 million for year ended December 31, 2018 at both Dominion Energy and Virginia Power.

[3] See Notes 9 and 25 for amounts attributable to related parties and affiliates.