Operating Revenue (Schedule of Operating Revenue) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		$ 13,752	$ 13,745	$ 10,891
Other revenues	[1],[2]	420	656	308
Total operating revenue		14,172	14,401	11,199
Regulated Electric Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		4,833	4,325	3,413
Regulated Electric Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		3,102	3,219	2,503
Regulated Electric Sales | Industrial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		730	683	490
Regulated Electric Sales | Government and Other Retail
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		868	873	854
Regulated Electric Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		128	176	137
Nonregulated Electric Sales
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		803	926	1,294
Regulated Gas Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		1,283	1,343	818
Regulated Gas Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		457	457	221
Regulated Gas Sales | Other
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		88	109	11
Nonregulated Gas Sales
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		174	495	210
Regulated Gas Transportation and Storage
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		801	742	640
Other Regulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		327	252	178
Other Nonregulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[3],[4]	158	145	122
Virginia Electric and Power Company
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		7,661	8,036	7,584
Other revenues	[1],[4]	102	72	35
Total operating revenue		7,763	8,108	7,619
Virginia Electric and Power Company | Regulated Electric Sales | Residential
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		3,677	3,657	3,413
Virginia Electric and Power Company | Regulated Electric Sales | Commercial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		2,342	2,712	2,503
Virginia Electric and Power Company | Regulated Electric Sales | Industrial
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		380	455	490
Virginia Electric and Power Company | Regulated Electric Sales | Government and Other Retail
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		804	823	854
Virginia Electric and Power Company | Regulated Electric Sales | Wholesale
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		90	128	137
Virginia Electric and Power Company | Other Regulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers		299	190	132
Virginia Electric and Power Company | Other Nonregulated Revenues
Public Utilities General Disclosures [Line Items]
Operating revenue from contracts with customers	[3],[4]	$ 69	$ 71	$ 55

[1] Amounts above include alternative revenue of $119 million and $82 million for the year ended December 31, 2020 at Dominion Energy and Virginia Power, $66 million and $52 million for 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.

[2] Amounts above include revenue associated with services provided to entities presented in discontinued operations of $4 million for the year ended December 31, 2020 and $6 million for both years ended December 31, 2019 and 2018.

[3] Amounts above include sales which are considered to be goods transferred at a point in time. For the years ended December 31, 2020, 2019 and 2018, such amounts included $22 million, $37 million and $19 million, respectively, at Dominion Energy, primarily consisting of sales of commodities related to nonregulated extraction activities and other miscellaneous products. Additionally, amounts above include sales of renewable energy credits. For the years ended December 31, 2020, 2019 and 2018, such sales were $20 million, $24 million and $17 million, respectively, at Dominion Energy and $11 million, $17 million and $11 million, respectively, at Virginia Power.

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