Income Taxes (Narrative) (Detail) - USD ($)		1 Months Ended		12 Months Ended
		Sep. 30, 2023	Aug. 31, 2022	Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022		Jul. 31, 2023	Dec. 31, 2021
Income Taxes [Line Items]
State deferred income tax expense (benefit)				$ 60,000,000		$ 277,000,000		$ 59,000,000
Income tax expense (benefit)				308,000,000	[1]	568,000,000	[2]	59,000,000	[3]
Income tax expense (benefit) from discontinued operations				31,000,000		1,300,000,000		207,000,000
Discontinued operations, deferred tax liabilities		$ 939,000,000
Deferred income taxes				(302,000,000)		1,474,000,000		58,000,000
Income tax benefit associated with remeasurement of state deferred taxes				(40,000,000)		(45,000,000)		(35,000,000)
Unrecognized tax benefits				78,000,000		110,000,000		117,000,000			$ 128,000,000
Unrecognized tax benefits that would impact effective tax rate				30,000,000		52,000,000		64,000,000
Pre-tax income				2,182,000,000		2,724,000,000		328,000,000
Maximum
Income Taxes [Line Items]
Decrease in Unrecognized tax benefits due to settlement negotiations and expiration of statutes of limitations				38,000,000
Amount that earnings could potentially increase if changes were to occur				30,000,000
Cove Point
Income Taxes [Line Items]
Income tax expense (benefit) from discontinued operations						$ 31,000,000		92,000,000
East Ohio, PSNC and Questar Gas
Income Taxes [Line Items]
Income tax expense (benefit)				(39,000,000)
Discontinued operations, deferred tax liabilities				851,000,000
East Ohio, PSNC and Questar Gas | Cove Point
Income Taxes [Line Items]
Percentage of noncontrolling limited partnership interest retained		50.00%				50.00%
Income tax expense (benefit)						$ 29,000,000
Virginia Electric and Power Company
Income Taxes [Line Items]
State deferred income tax expense (benefit)				60,000,000		107,000,000		108,000,000
Income tax expense (benefit)	[4]			408,000,000		389,000,000		294,000,000
Production tax credit				89,000,000
Deferred income taxes				384,000,000		504,000,000		141,000,000
Income tax benefit associated with remeasurement of state deferred taxes				0		0		0
Unrecognized tax benefits				0		0		0
Hope Gas Inc [Member]
Income Taxes [Line Items]
Income tax expense (benefit)								34,000,000
Percentage of equity interests sold			100.00%
Discontinued Operations
Income Taxes [Line Items]
Unrecognized tax benefits that would impact effective tax rate				32,000,000		38,000,000		33,000,000
Discontinued Operations | East Ohio [Member]
Income Taxes [Line Items]
Income tax expense (benefit)				(11,000,000)
Pre-tax income				60,000,000
Discontinued Operations | PSNC
Income Taxes [Line Items]
Income tax expense (benefit)						(59,000,000)
Pre-tax income						116,000,000
Discontinued Operations | Questar Gas [Member]
Income Taxes [Line Items]
Income tax expense (benefit)								(38,000,000)
Pre-tax income								242,000,000
Discontinued Operations | East Ohio, PSNC and Questar Gas
Income Taxes [Line Items]
Income tax charge		$ 835,000,000
Continuing Operations
Income Taxes [Line Items]
Increase (Decrease) in tax expense as a result of changes in unrecognized tax benefits				$ (22,000,000)		$ (8,000,000)		$ (7,000,000)
BHE | East Ohio, PSNC and Questar Gas | Cove Point
Income Taxes [Line Items]
Income tax expense (benefit) from discontinued operations		$ 278,000,000
IRA
Income Taxes [Line Items]
Percentage of alternate minimum tax on GAAP net income			15.00%
IRA | Minimum
Income Taxes [Line Items]
Tax credit expiration year			2032
Annual financial statement income for tax years			$ 1,000,000,000
GT&S Transaction | BHE | Cove Point
Income Taxes [Line Items]
Percentage of noncontrolling limited partnership interest retained										50.00%

[1] The significant expense categories and amounts in the segment information presented above align with the segment-level information that is regularly provided to Dominion Energy’s CODM.

[2] The significant expense categories and amounts in the segment information presented above align with the segment-level information that is regularly provided to Dominion Energy’s CODM.

[3] The significant expense categories and amounts in the segment information presented above align with the segment-level information that is regularly provided to Dominion Energy’s CODM.

[4] The significant expense categories and amounts in the segment information presented above align with the segment-level information that is regularly provided to Virginia Power’s CODM.