Significant Financing Transactions (Narrative) (Detail) - USD ($)				1 Months Ended				3 Months Ended
		Sep. 01, 2022	May 05, 2022	Jun. 30, 2022	May 31, 2022	Apr. 30, 2022	Jan. 31, 2022	Aug. 31, 2022	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021		Nov. 30, 2020	Jul. 31, 2020
Debt Instrument [Line Items]
Facility Limit	[1]								$ 6,000,000,000
Short-term debt									$ 2,548,000,000		$ 2,314,000,000	[2]
Preferred stock shares authorized									20,000,000
Stock purchase contract liability									$ 22,000,000		44,000,000
Corporate units stock purchase contract liability payments									22,000,000	$ 21,000,000
Issuance of common stock									45,000,000	48,000,000
Issuance of stock									$ 45,000,000	48,000,000
Common Stock
Debt Instrument [Line Items]
Stock repurchased, shares									0
Issuance of stock (in shares)									1,000,000
Issuance of stock									$ 45,000,000	48,000,000
Stock repurchase program, authorized amount													$ 1,000,000,000.0	$ 3,000,000,000.0
2019 Series A Corporate Units | Forecast
Debt Instrument [Line Items]
Stock issued during period for conversion, value				$ 1,600,000,000
2019 Series A Corporate Units | Maximum | Forecast
Debt Instrument [Line Items]
Shares to be issued under purchase contracts				21,800,000
Series A Preferred Stock
Debt Instrument [Line Items]
Recorded dividend									$ 7,000,000	$ 7,000,000
Recorded dividends per share									$ 4.375	$ 4.375
Series A Preferred Stock | 2019 Series A Corporate Units
Debt Instrument [Line Items]
Stock repurchased, shares			1,600,000
Series A Preferred Stock | 2019 Series A Corporate Units | Forecast
Debt Instrument [Line Items]
Preferred stock dividend rate percentage								1.75%
Preferred stock dividend rate increase percentage		6.75%
Series B Preferred Stock
Debt Instrument [Line Items]
Recorded dividend									$ 9,000,000	$ 9,000,000
Recorded dividends per share									$ 11.625	$ 11.625
Series C Preferred Stock
Debt Instrument [Line Items]
Recorded dividend									$ 11,000,000
Recorded dividends per share									$ 10,875,000
Various Programs
Debt Instrument [Line Items]
Issuance of common stock									$ 45,000,000	$ 48,000,000
Issuance of stock (in shares)									1,000,000
Various Programs | Maximum
Debt Instrument [Line Items]
Issuance of stock (in shares)										1,000,000
Floating Rate Demand Notes
Debt Instrument [Line Items]
Short-term debt									$ 473,000,000		431,000,000
Floating Rate Demand Notes | Shelf Registration for Sale of Demand Notes
Debt Instrument [Line Items]
Facility Limit											3,000,000,000.0
Subsequent Event | Common Stock
Debt Instrument [Line Items]
Issuance of stock (in shares)					900,000
Issuance of stock					$ 72,000,000
Subsequent Event | 2019 Series A Corporate Units | Maximum
Debt Instrument [Line Items]
Short-term deposit			$ 2,000,000,000.0
Subsequent Event | 2019 Series A Corporate Units | Minimum [Member]
Debt Instrument [Line Items]
Short-term deposit			1,600,000,000
DESC
Debt Instrument [Line Items]
Facility Limit									500,000,000
Questar Gas Company
Debt Instrument [Line Items]
Facility Limit									250,000,000
Virginia Electric and Power Company
Debt Instrument [Line Items]
Facility Limit	[3]								6,000,000,000
Short-term debt									$ 686,000,000		$ 745,000,000	[4]
Issuance of stock (in shares)									0	0
Virginia Electric and Power Company | Senior Notes Due in 2032
Debt Instrument [Line Items]
Total Long-term Debt							$ 600,000,000
Interest rate percentage							2.40%
Debt maturity year							2032
Virginia Electric and Power Company | Senior Notes Due in 2051
Debt Instrument [Line Items]
Total Long-term Debt							$ 400,000,000
Interest rate percentage							2.95%
Debt maturity year							2051
Virginia Electric and Power Company | Subsequent Event
Debt Instrument [Line Items]
Interest rate percentage						1.65%
Aggregate outstanding principal						$ 138,000,000
Debt, maturity month and year						2024-05
Dominion Energy
Debt Instrument [Line Items]
Preferred stock shares issued									3,400,000		3,400,000
Preferred stock shares outstanding									3,400,000		3,400,000
Dominion Energy | Series A Preferred Stock
Debt Instrument [Line Items]
Preferred stock shares issued									1,600,000		1,600,000
Preferred stock shares outstanding									1,600,000		1,600,000
Dominion Energy | Series B Preferred Stock
Debt Instrument [Line Items]
Preferred stock shares issued									800,000		800,000
Preferred stock shares outstanding									800,000		800,000
Dominion Energy | Series C Preferred Stock
Debt Instrument [Line Items]
Preferred stock shares issued									1,000,000.0		1,000,000.0
Preferred stock shares outstanding									1,000,000.0		1,000,000.0
New Joint Revolving Credit Facility
Debt Instrument [Line Items]
Facility Limit									$ 6,000,000,000.0
Letter of Credit
Debt Instrument [Line Items]
Facility Limit									2,000,000,000.0
Letter of Credit | Credit Facility, Maturing in June 2022
Debt Instrument [Line Items]
Facility Limit									30,000,000
Credit facility, outstanding amount									$ 20,000,000		$ 29,000,000
Line of credit facility, maturity date									Jun. 30, 2022
Letter of Credit | Subsequent Event
Debt Instrument [Line Items]
Line of credit facility, extended maturity date						Jun. 30, 2025
Letter of Credit | Virginia Electric and Power Company
Debt Instrument [Line Items]
Facility Limit									$ 2,000,000,000.0
Sustainability Revolving Credit Facility | Virginia Electric and Power Company | Subsequent Event
Debt Instrument [Line Items]
Facility Limit			$ 900,000,000
Debt maturity year			2024

[1] This credit facility matures in June 2026, with the potential to be extended by the borrowers to June 2028, and can be used by the borrowers under the credit facility to support bank borrowings and the issuance of commercial paper, as well as to support up to a combined $2.0 billion of letters of credit.

[2] Dominion Energy’s Consolidated Balance Sheet at December 31, 2021 has been derived from the audited Consolidated Balance Sheet at that date.

[3] The full amount of the facility is available to Virginia Power, less any amounts outstanding to co-borrowers Dominion Energy, Questar Gas and DESC. The sub-limit for Virginia Power is set pursuant to the terms of the facility but can be changed at the option of the borrowers multiple times per year. At March 31, 2022, the sub-limit for Virginia Power was $1.75 billion. If Virginia Power has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. This credit facility matures in June 2026, with the potential to be extended by the borrowers to June 2028. The credit facility can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $2.0 billion (or the sub-limit, whichever is less) of letters of credit.

[4] Virginia Power’s Consolidated Balance Sheet at December 31, 2021 has been derived from the audited Consolidated Balance Sheet at that date.