Significant Financing Transactions (Narrative) (Detail) - USD ($)		1 Months Ended		3 Months Ended		7 Months Ended	12 Months Ended
		Apr. 30, 2025	Feb. 28, 2025	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Dec. 31, 2024		Jan. 31, 2025	Jun. 30, 2024	Mar. 31, 2023	Nov. 30, 2020	Nov. 30, 2017
Debt Instrument [Line Items]
Facility Limit	[1]			$ 6,000,000,000		$ 6,000,000,000
Short-term debt				2,084,000,000		$ 2,084,000,000	$ 2,500,000,000	[2]
Line of credit issued				$ 0	$ 3,000,000,000
Preferred stock shares authorized				20,000,000		20,000,000
Dividend stock				$ 11,000,000	20,000,000
Borrowings outstanding				0		$ 0	0
Issuance of common stock				$ 35,000,000	$ 31,000,000
Subsequent Event
Debt Instrument [Line Items]
Facility Limit		$ 1,000,000,000
Line of credit facility, maturity date		Apr. 30, 2026
Common Stock
Debt Instrument [Line Items]
Stock repurchased, shares				0
Issuance of stock (in shares)				1,000,000	0
Stock repurchase program, authorized amount				$ 900,000,000		$ 900,000,000						$ 1,000,000,000
Series B Preferred Stock
Debt Instrument [Line Items]
Recorded dividend					$ 9,000,000
Dividends per share					$ 11.625
Various Programs
Debt Instrument [Line Items]
Issuance of common stock				$ 35,000,000	$ 31,000,000
Issuance of stock (in shares)				1,000,000
Various Programs | Maximum
Debt Instrument [Line Items]
Issuance of stock (in shares)					1,000,000
Sales Agency Agreements to Effect Sales Under At-the-market Program | Maximum
Debt Instrument [Line Items]
Sale of stock authorized amount			$ 1,200,000,000
Forward Sale Agreements
Debt Instrument [Line Items]
Weighted average initial forward price per share				$ 55.34
Forward sale agreements, number of shares of common stock to be settled				8,800,000		8,800,000
Aggregate Forward Sale Agreement
Debt Instrument [Line Items]
Weighted average initial forward price per share						$ 56.62
Forward sale agreements, number of shares of common stock to be settled				18,500,000		18,500,000
Floating Rate Demand Notes
Debt Instrument [Line Items]
Short-term debt				$ 446,000,000		$ 446,000,000	439,000,000
Floating Rate Demand Notes | Shelf Registration for Sale of Demand Notes
Debt Instrument [Line Items]
Facility Limit													$ 3,000,000,000
DESC
Debt Instrument [Line Items]
Facility Limit				500,000,000		500,000,000
Short-term indebtedness outstanding				1,800,000,000
DESC | Subsequent Event
Debt Instrument [Line Items]
Facility Limit		$ 1,000,000,000
GENCO
Debt Instrument [Line Items]
Short-term indebtedness outstanding				300,000,000
Virginia Electric and Power Company
Debt Instrument [Line Items]
Facility Limit				6,000,000,000		6,000,000,000
Short-term debt				$ 244,000,000		$ 244,000,000	$ 950,000,000	[3]
Issuance of stock (in shares)				0	0
Virginia Electric and Power Company | Subsequent Event
Debt Instrument [Line Items]
Facility Limit		3,000,000,000
Virginia Electric and Power Company | Senior Notes Due In 2035
Debt Instrument [Line Items]
Debt instrument maturity year				2035
Interest Rate				5.15%		5.15%
Debt issued amount				$ 625,000,000		$ 625,000,000
Virginia Electric and Power Company | Senior Notes Due In 2055
Debt Instrument [Line Items]
Debt instrument maturity year				2055
Interest Rate				5.65%		5.65%
Debt issued amount				$ 625,000,000		$ 625,000,000
Dominion Energy | Series C Preferred Stock
Debt Instrument [Line Items]
Preferred stock shares outstanding				1,000,000		1,000,000	1,000,000
Dividend stock				$ 11,000,000	$ 11,000,000
Preferred stock dividend per share				$ 10.875	$ 10.875
Dominion Energy | Senior Notes Due In February 2024
Debt Instrument [Line Items]
Recorded interest expense					$ 10,000,000
Dominion Energy | Senior Notes Due In 2030
Debt Instrument [Line Items]
Debt instrument maturity year				2030
Interest Rate				5.00%		5.00%
Debt issued amount				$ 800,000,000		$ 800,000,000
Dominion Energy | Senior Notes Due In 2035
Debt Instrument [Line Items]
Debt instrument maturity year				2035
Interest Rate				5.45%		5.45%
Debt issued amount				$ 700,000,000		$ 700,000,000
DESC | First Mortgage Bonds Due in 2035
Debt Instrument [Line Items]
Interest Rate									5.30%
Debt issued amount									$ 450,000,000
Joint Revolving Credit Facility
Debt Instrument [Line Items]
Facility Limit				6,000,000,000		6,000,000,000
Joint Revolving Credit Facility | Subsequent Event
Debt Instrument [Line Items]
Facility Limit		7,000,000,000
Letter of Credit
Debt Instrument [Line Items]
Facility Limit											$ 100,000,000
Letters of credit issued and outstanding				44,000,000		44,000,000	$ 48,000,000
Letter of Credit | Credit Facility, Maturing in June 2024
Debt Instrument [Line Items]
Facility Limit										$ 275,000,000
Letters of credit issued and outstanding				89,000,000		89,000,000	88,000,000
Letter of Credit | Credit Facility Maturing In April 2030 | Subsequent Event
Debt Instrument [Line Items]
Facility Limit		$ 3,000,000,000
Line of credit facility, maturity date		Apr. 30, 2030
Letter of Credit | Credit Facility Maturing In June 2026
Debt Instrument [Line Items]
Facility Limit				$ 2,000,000,000		2,000,000,000
Line of credit facility, maturity date				Jun. 30, 2026
Letter of Credit | Credit Facility in January 2025
Debt Instrument [Line Items]
Facility Limit									150,000,000
Letters of credit issued and outstanding				$ 52,000,000		52,000,000
Letter of Credit | Credit Facility Through March 2025
Debt Instrument [Line Items]
Letters of credit issued and outstanding				50,000,000		50,000,000
Letter of Credit | DESC | Credit Facility, Maturing in June 2024
Debt Instrument [Line Items]
Letters of credit issued and outstanding				89,000,000		89,000,000	88,000,000
Letter of Credit | DESC | Credit Facility in January 2025
Debt Instrument [Line Items]
Facility Limit									50,000,000
Letter of Credit | Virginia Electric and Power Company
Debt Instrument [Line Items]
Facility Limit				3,000,000,000		3,000,000,000					$ 300,000,000
Line of credit issued				161,000,000			112,000,000
Letter of Credit | Virginia Electric and Power Company | Credit Facility, Maturing in June 2024
Debt Instrument [Line Items]
Facility Limit										$ 275,000,000
Letters of credit issued and outstanding				78,000,000		78,000,000	$ 77,000,000
Letter of Credit | Virginia Electric and Power Company | Credit Facility in January 2025
Debt Instrument [Line Items]
Facility Limit									$ 100,000,000
Letters of credit issued and outstanding				50,000,000		50,000,000
Line of Credit Sub-limit [Member] | Virginia Electric and Power Company
Debt Instrument [Line Items]
Facility Limit				$ 1,750,000,000		$ 1,750,000,000
Sustainability Revolving Credit Facility | Credit Facility Maturing In June 2025 | Subsequent Event
Debt Instrument [Line Items]
Facility Limit		$ 900,000,000
Line of credit facility, maturity date		Apr. 30, 2028
Sustainability Revolving Credit Facility | Credit Facility Maturing In April 2028 | Subsequent Event
Debt Instrument [Line Items]
Facility Limit		$ 1,000,000,000
Line of credit facility, maturity date		Apr. 30, 2030

[1] This credit facility, as amended in April 2025, matures in April 2030, with the potential to be extended by the borrowers to April 2032, 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 $3.0 billion of letters of credit

[2] Dominion Energy’s Consolidated Balance Sheet at December 31, 2024 has been derived from the audited Consolidated Balance Sheet at that date.

[3] Virginia Power’s Consolidated Balance Sheet at December 31, 2024 has been derived from the audited Consolidated Balance Sheet at that date.