Operating Segments (Schedule of Segment Reporting Information, by Segment) (Detail) - USD ($) $ in Millions			1 Months Ended	12 Months Ended
		Nov. 30, 2020	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating Revenue				$ 13,964	$ 14,172	$ 14,401
Depreciation, depletion and amortization				2,478	2,332	2,283
Equity in earnings of equity method investees				276	40	8
Interest income				101	107	97
Interest and related charges				1,354	1,377	1,486
Income tax expense		$ 336	$ 173	425	83	209
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interest	[1],[2]			641	(1,878)	716
Net income (loss) attributable to Dominion Energy				3,288	(401)	1,358
Investment in equity method affiliates	[3]		2,932	2,932	2,934
Capital expenditures				6,061	6,331	5,321
Total assets			99,590	99,590	95,905
Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue				13,959	14,197	14,408
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Operating Revenue				60	48	79
Depreciation, depletion and amortization				0	0	0
Equity in earnings of equity method investees				0	0	0
Interest income				(26)	(88)	(136)
Interest and related charges				(26)	(88)	(136)
Income tax expense				0	0	0
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interest				0	0	0
Net income (loss) attributable to Dominion Energy				0	0	0
Investment in equity method affiliates	[3]		0	0	0
Capital expenditures				0	0	0
Total assets			(5,000)	(5,000)	(4,900)
Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue				5	(25)	(7)
Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue				(1,004)	(1,039)	(1,160)
Eliminations
Segment Reporting Information [Line Items]
Operating Revenue				(944)	(991)	(1,081)
Dominion Energy Virginia
Segment Reporting Information [Line Items]
Operating Revenue				7,999	7,787	8,157
Dominion Energy Virginia | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue				8,012	7,802	8,170
Depreciation, depletion and amortization				1,299	1,247	1,216
Equity in earnings of equity method investees				0	0	0
Interest income				13	13	11
Interest and related charges				537	527	530
Income tax expense				462	496	482
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interest				0	0	0
Net income (loss) attributable to Dominion Energy				1,919	1,891	1,786
Investment in equity method affiliates	[3]		0	0	0
Capital expenditures				3,762	3,406	3,002
Total assets			50,300	50,300	46,000
Dominion Energy Virginia | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue				(13)	(15)	(13)
Gas Distribution
Segment Reporting Information [Line Items]
Operating Revenue				2,665	2,355	2,385
Gas Distribution | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue				2,660	2,345	2,367
Depreciation, depletion and amortization				380	344	335
Equity in earnings of equity method investees				0	0	2
Interest income				6	6	4
Interest and related charges				86	76	116
Income tax expense				116	121	114
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interest				0	0	0
Net income (loss) attributable to Dominion Energy				600	560	487
Investment in equity method affiliates	[3]		106	106	55
Capital expenditures				1,252	1,151	853
Total assets			18,500	18,500	17,100
Gas Distribution | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue				5	10	18
Dominion Energy South Carolina
Segment Reporting Information [Line Items]
Operating Revenue				2,975	2,787	2,952
Dominion Energy South Carolina | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue				2,968	2,782	2,948
Depreciation, depletion and amortization				486	474	452
Equity in earnings of equity method investees				(3)	(1)	(4)
Interest income				10	12	9
Interest and related charges				206	219	242
Income tax expense				125	107	163
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interest				0	0	0
Net income (loss) attributable to Dominion Energy				437	419	430
Investment in equity method affiliates	[3]		0	0	0
Capital expenditures				694	700	562
Total assets			16,400	16,400	16,000
Dominion Energy South Carolina | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue				7	5	4
Contracted Assets
Segment Reporting Information [Line Items]
Operating Revenue				1,085	1,071	1,156
Contracted Assets | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue				1,018	1,020	1,083
Depreciation, depletion and amortization				162	182	180
Equity in earnings of equity method investees				259	35	(1)
Interest income				81	91	97
Interest and related charges				52	75	98
Income tax expense				112	(16)	20
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interest				0	167	183
Net income (loss) attributable to Dominion Energy				431	402	460
Investment in equity method affiliates	[3]		2,738	2,738	2,784
Capital expenditures				277	649	367
Total assets			12,300	12,300	13,100
Contracted Assets | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue				67	51	73
Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenue				184	1,163	832
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue				(759)	200	(239)
Depreciation, depletion and amortization				151	85	100
Equity in earnings of equity method investees				20	6	11
Interest income				17	73	112
Interest and related charges				499	568	636
Income tax expense				(390)	(625)	(570)
Net Income (Loss) From Discontinued Operations Including Noncontrolling Interest				641	(2,045)	533
Net income (loss) attributable to Dominion Energy				(99)	(3,673)	(1,805)
Investment in equity method affiliates	[3]		88	88	95
Capital expenditures				76	425	537
Total assets			$ 7,100	7,100	8,600
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Operating Revenue				$ 943	$ 963	$ 1,071

[1] Includes income tax expense (benefit) of $188 million, $(204) million and $142 million for the years ended December 31, 2021, 2020 and 2019, respectively

[2] See Note 9 for amounts attributable to related parties

[3] Excludes liability to Atlantic Coast Pipeline.