Operating Segments (Schedule of Segment Reporting Information, by Segment) (Detail) - USD ($) $ in Millions	3 Months Ended										12 Months Ended
	Dec. 31, 2024		Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023		Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022
Segment Reporting Information [Line Items]
Total Operating Revenue	$ 3,400		$ 3,941	$ 3,486	$ 3,632	$ 3,534		$ 3,810	$ 3,166	$ 3,883	$ 14,459		$ 14,393		$ 13,938
Electric fuel and other energy-related purchases											3,614	[1]	3,935	[2]	3,711	[3]
Purchased electric capacity											74	[1]	55	[2]	59	[3]
Purchased gas											260	[1]	285	[2]	426	[3]
Other operations and maintenance											4,188	[1],[4]	3,440	[2],[5]	5,178	[3],[6]
Depreciation and amortization											2,345	[1]	2,580	[2]	2,442	[3]
Other taxes											731	[1]	684	[2]	675	[3]
Total operating expenses											11,212		10,979		12,491
Interest and related charges											1,887	[1]	1,674	[2]	1,002	[3]
Income tax expense (benefit)											308	[1]	568	[2]	59	[3]
Equity in earnings (losses) of equity method investees											3	[7]	(26)	[8]	21	[9]
Other income (expense)											694	[7]	903	[8]	(247)	[9]
Interest income											125	[7]	107	[8]	109	[9]
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interests	(3)		(15)	97	118	(33)		(541)	168	281	197	[10]	(125)	[10]	922	[10]
Noncontrolling Interests	(53)		0	0	0						(53)		0		0
Net Income	145		$ 958	$ 580	$ 441	331		$ 153	$ 575	$ 972	2,124		2,031		1,191
Investment in equity method investees	138	[11]				268	[12]				138	[11]	268	[12]
Capital expenditures											12,427		10,235		7,758
Total assets (billions)	102,415					109,080					102,415		109,080
Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers											14,459		14,393		13,938
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Total revenue from external customers											0		0		0
Total Operating Revenue											(1,030)		(959)		(859)
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Electric fuel and other energy-related purchases											(6)	[1]	(10)	[2]	(11)	[3]
Purchased electric capacity											(2)	[1]	(3)	[2]	(3)	[3]
Purchased gas											0	[1]	0	[2]	0	[3]
Other operations and maintenance											(1,014)	[1],[4]	(939)	[2],[5]	(839)	[3],[6]
Depreciation and amortization											0	[1]	0	[2]	0	[3]
Other taxes											(8)	[1]	(7)	[2]	(6)	[3]
Total operating expenses											(1,030)		(959)		(859)
Interest and related charges											(187)	[1]	(206)	[2]	(50)	[3]
Income tax expense (benefit)											0	[1]	0	[2]	0	[3]
Equity in earnings (losses) of equity method investees											0	[7]	0	[8]	0	[9]
Other income (expense)											0	[7]	0	[8]	0	[9]
Interest income											(187)	[7]	(206)	[8]	(50)	[9]
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interests											0		0		0
Noncontrolling Interests											0
Net Income											0		0		0
Investment in equity method investees	0	[11]				0	[12]				0	[11]	0	[12]
Capital expenditures											0		0		0
Total assets (billions)	(5,700)					(4,100)					(5,700)		(4,100)
Intersegment revenue
Segment Reporting Information [Line Items]
Total Operating Revenue											0		0		0
Intersegment revenue
Segment Reporting Information [Line Items]
Total Operating Revenue											(1,030)		(959)		(859)
Dominion Energy Virginia | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers											10,226		9,575		9,658
Total Operating Revenue											10,235		9,573		9,643
Electric fuel and other energy-related purchases											2,743	[1]	2,918	[2]	2,913	[3]
Purchased electric capacity											68	[1]	46	[2]	38	[3]
Purchased gas											0	[1]	0	[2]	0	[3]
Other operations and maintenance											2,217	[1],[4]	1,842	[2],[5]	1,956	[3],[6]
Depreciation and amortization											1,635	[1]	1,622	[2]	1,452	[3]
Other taxes											332	[1]	298	[2]	301	[3]
Total operating expenses											6,995		6,726		6,660
Interest and related charges											856	[1]	772	[2]	645	[3]
Income tax expense (benefit)											443	[1]	471	[2]	514	[3]
Equity in earnings (losses) of equity method investees											0	[7]	0	[8]	0	[9]
Other income (expense)											100	[7]	65	[8]	64	[9]
Interest income											20	[7]	15	[8]	17	[9]
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interests											0		0		0
Noncontrolling Interests											50
Net Income											2,011		1,684		1,905
Investment in equity method investees	0	[11]				0	[12]				0	[11]	0	[12]
Capital expenditures											9,968		7,196		5,187
Total assets (billions)	70,000					60,700					70,000		60,700
Dominion Energy Virginia | Intersegment revenue
Segment Reporting Information [Line Items]
Total Operating Revenue											9		(2)		(15)
Dominion Energy South Carolina | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers											3,295		3,369		3,323
Total Operating Revenue											3,304		3,375		3,330
Electric fuel and other energy-related purchases											775	[1]	947	[2]	719	[3]
Purchased electric capacity											8	[1]	12	[2]	15	[3]
Purchased gas											260	[1]	285	[2]	383	[3]
Other operations and maintenance											671	[1],[4]	612	[2],[5]	604	[3],[6]
Depreciation and amortization											546	[1]	531	[2]	507	[3]
Other taxes											292	[1]	285	[2]	269	[3]
Total operating expenses											2,552		2,672		2,497
Interest and related charges											276	[1]	249	[2]	220	[3]
Income tax expense (benefit)											80	[1]	79	[2]	132	[3]
Equity in earnings (losses) of equity method investees											0	[7]	0	[8]	0	[9]
Other income (expense)											(5)	[7]	(4)	[8]	18	[9]
Interest income											7	[7]	6	[8]	6	[9]
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interests											0		0		0
Noncontrolling Interests											0
Net Income											398		377		505
Investment in equity method investees	0	[11]				0	[12]				0	[11]	0	[12]
Capital expenditures											1,105		957		708
Total assets (billions)	18,400					17,300					18,400		17,300
Dominion Energy South Carolina | Intersegment revenue
Segment Reporting Information [Line Items]
Total Operating Revenue											9		6		7
Contracted Energy | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers											1,099		835		884
Total Operating Revenue											1,109		851		902
Electric fuel and other energy-related purchases											102	[1]	80	[2]	90	[3]
Purchased electric capacity											0	[1]	0	[2]	0	[3]
Purchased gas											0	[1]	0	[2]	0	[3]
Other operations and maintenance											487	[1],[4]	544	[2],[5]	448	[3],[6]
Depreciation and amortization											76	[1]	105	[2]	123	[3]
Other taxes											53	[1]	48	[2]	43	[3]
Total operating expenses											718		777		704
Interest and related charges											36	[1]	44	[2]	18	[3]
Income tax expense (benefit)											105	[1]	15	[2]	55	[3]
Equity in earnings (losses) of equity method investees											9	[7]	(34)	[8]	2	[9]
Other income (expense)											(15)	[7]	22	[8]	(14)	[9]
Interest income											115	[7]	96	[8]	75	[9]
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interests											0		0		0
Noncontrolling Interests											0
Net Income											359		99		188
Investment in equity method investees	91	[11]				80	[12]				91	[11]	80	[12]
Capital expenditures											772		740		683
Total assets (billions)	9,500					9,100					9,500		9,100
Contracted Energy | Intersegment revenue
Segment Reporting Information [Line Items]
Total Operating Revenue											10		16		18
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers											(161)		614		73
Total Operating Revenue											841		1,553		922
Electric fuel and other energy-related purchases											0	[1]	0	[2]	0	[3]
Purchased electric capacity											0	[1]	0	[2]	9	[3]
Purchased gas											0	[1]	0	[2]	43	[3]
Other operations and maintenance											1,827	[1],[4]	1,381	[2],[5]	3,009	[3],[6]
Depreciation and amortization											88	[1]	322	[2]	360	[3]
Other taxes											62	[1]	60	[2]	68	[3]
Total operating expenses											1,977		1,763		3,489
Interest and related charges											906	[1]	815	[2]	169	[3]
Income tax expense (benefit)											(320)	[1]	3	[2]	(642)	[3]
Equity in earnings (losses) of equity method investees											(6)	[7]	8	[8]	19	[9]
Other income (expense)											614	[7]	820	[8]	(315)	[9]
Interest income											170	[7]	196	[8]	61	[9]
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interests											197		(125)		922
Noncontrolling Interests											(103)
Net Income											(644)		(129)		(1,407)
Investment in equity method investees	47	[11]				188	[12]				47	[11]	188	[12]
Capital expenditures											582		1,342		1,180
Total assets (billions)	$ 10,200					$ 26,100					10,200		26,100
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Total Operating Revenue											$ 1,002		$ 939		$ 849

[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] Includes impairment of assets and other charges (benefits) and losses (gains) on sale of assets.

[5] Includes impairment of assets and other charges (benefits) and losses (gains) on sale of assets.

[6] Includes impairment of assets and other charges (benefits) and losses (gains) on sale of assets.

[7] Items designated are other segment items for each reportable segment.

[8] Items designated are other segment items for each reportable segment.

[9] Items designated are other segment items for each reportable segment.

[10] Includes income tax expense of $31 million, $1.3 billion and $207 million for the years ended December 31, 2024, 2023 and 2022, respectively.

[11] Excludes liability to Atlantic Coast Pipeline.

[12] Excludes liability to Atlantic Coast Pipeline.