Operating Revenue (Schedule of Operating Revenue) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		$ 4,323	$ 3,631
Other revenues	[1]	173	227
Total operating revenue		4,496	3,858
Regulated Electric Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		1,158	646
Regulated Electric Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		798	496
Regulated Electric Sales | Industrial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		182	30
Regulated Electric Sales | Government and Other Retail
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		219	200
Regulated Electric Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		33	48
Nonregulated Electric Sales
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		232	316
Regulated Gas Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		548	602
Regulated Gas Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		191	191
Regulated Gas Sales | Other
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		28	38
Nonregulated Gas Sales
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		83	247
Regulated Gas Transportation and Storage | FERC-regulated
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		281	277
Regulated Gas Transportation and Storage | State-regulated
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		232	213
Nonregulated gas transportation and storage
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		175	174
Other Regulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2]	75	58
Other Nonregulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2],[3]	88	95
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		1,909	1,951
Other revenues	[1],[3]	21	14
Total operating revenue		1,930	1,965
Virginia Electric and Power Company | Regulated Electric Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		896	923
Virginia Electric and Power Company | Regulated Electric Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		614	636
Virginia Electric and Power Company | Regulated Electric Sales | Industrial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		97	112
Virginia Electric and Power Company | Regulated Electric Sales | Government and Other Retail
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		203	204
Virginia Electric and Power Company | Regulated Electric Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		24	37
Virginia Electric and Power Company | Other Regulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[3]	62	33
Virginia Electric and Power Company | Other Nonregulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2],[3]	13	6
Dominion Energy Gas Holdings, LLC
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		555	565
Other revenues		1	1
Total operating revenue		556	566
Dominion Energy Gas Holdings, LLC | Regulated Gas Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		2	2
Dominion Energy Gas Holdings, LLC | Regulated Gas Transportation and Storage
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		344	340
Dominion Energy Gas Holdings, LLC | Nonregulated gas transportation and storage
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		175	174
Dominion Energy Gas Holdings, LLC | Other Regulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2],[3]	1	3
Dominion Energy Gas Holdings, LLC | Other Nonregulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[2],[3]	1
Dominion Energy Gas Holdings, LLC | Nonregulated Gas Sale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[3]	1	2
Dominion Energy Gas Holdings, LLC | Management Service
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[3]	$ 31	$ 44

[1] Includes alternative revenue. For the three months ended March 31, 2020 and 2019, such amounts included $36 million and $14 million, respectively, at Dominion Energy and $17 million and $8 million, respectively, at Virginia Power.

[2] Amounts above include sales which are considered to be goods transferred at a point in time. For the three months ended March 31, 2020 and 2019, such amounts included $39 million and $48 million, respectively, at Dominion Energy and $1 million for both the three months ended March 31, 2020 and 2019, at Dominion Energy Gas, consisting of NGL sales. Additionally, amounts above include sales of renewable energy credits. For the three months ended March 31, 2020 and 2019, such sales were $4 million and $3 million, respectively, at Dominion Energy and $3 million and $1 million, respectively, at Virginia Power.

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