Investments (Narrative) (Detail)			1 Months Ended							3 Months Ended			12 Months Ended
		Nov. 30, 2020 USD ($)	May 31, 2022 USD ($)	Feb. 28, 2022 USD ($)	Dec. 31, 2021 USD ($)	Nov. 30, 2020	Sep. 30, 2020 USD ($)	Oct. 31, 2017 USD ($)	Sep. 30, 2014 mi	Dec. 31, 2022 USD ($)	Aug. 31, 2022	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019	Jun. 30, 2021 USD ($)	Jul. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investees													$ 299,000,000	$ 276,000,000	$ 40,000,000
Net income (loss) from discontinued operations including noncontrolling interest	[1],[2]												9,000,000	641,000,000	(1,878,000,000)
Distributions received from investment													355,000,000	328,000,000	102,000,000
Equity method investment goodwill					$ 27,000,000					$ 9,000,000			9,000,000	27,000,000
Income loss from continuing operations before income taxes extraordinary items noncontrolling interest													1,053,000,000	3,098,000,000	1,411,000,000
Contributions to equity method affiliates													43,000,000	1,021,000,000	148,000,000
Debt maximum borrowing capacity	[3]				6,000,000,000					6,000,000,000			6,000,000,000	6,000,000,000
Retained earnings					5,373,000,000					4,065,000,000			4,065,000,000	5,373,000,000
Operating revenue from contracts with customers													17,725,000,000	14,170,000,000	13,752,000,000
Goodwill write-off	[4]												110,000,000
Income tax expense		$ 336,000,000			173,000,000								68,000,000	425,000,000	83,000,000
Revolving Credit Facility
Schedule of Equity Method Investments [Line Items]
Debt maximum borrowing capacity																	$ 6,000,000,000.0
Pivotal LNG
Schedule of Equity Method Investments [Line Items]
Ownership percentage acquired																			100.00%
Finite Lived Equity Method Investment Basis Difference
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment that exceeded share of underlying equity					244,000,000					223,000,000			223,000,000	244,000,000
Unfunded commitments					$ (4,000,000)									(4,000,000)
Capitalized interest													(1,000,000)
Cove Point
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage of limited partner interests						100.00%
Income loss from continuing operations before income taxes extraordinary items noncontrolling interest													$ 574,000,000	$ 528,000,000	511,000,000
JAX LNG LLC | Pivotal LNG
Schedule of Equity Method Investments [Line Items]
Percentage of equity interest sold to noncontrolling interest owners																			50.00%
Fowler Ridge
Schedule of Equity Method Investments [Line Items]
Net payment of long-term power and capacity contract							$ 150,000,000
Contract termination loss															221,000,000
Contract termination loss net of tax															$ 165,000,000
Fowler Ridge | BP Wind Energy North America Inc
Schedule of Equity Method Investments [Line Items]
Percentage of equity interest sold to noncontrolling interest owners							50.00%
Wrangler Retail Gas Holdings LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage of limited partner interests														20.00%	20.00%	20.00%
Percentage ownership in total units					15.00%							15.00%		15.00%
Limited partnership interest sale transaction, proceeds received														$ 127,000,000	$ 74,000,000
Initial fair value					$ 23,000,000									23,000,000	13,000,000
Amount of gain from sale														87,000,000	64,000,000
Goodwill write-off														14,000,000
Income tax expense														$ 32,000,000	19,000,000
Wrangler Retail Gas Holdings LLC | Gas Supply, Inc.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage of limited partner interests													15.00%	5.00%
Cash consideration from sale of noncontrolling interest													$ 85,000,000
Amount of gain from sale													11,000,000	$ 10,000,000
Amount of gain from sale, after tax													8,000,000
Income tax expense														3,000,000
Sale of interest in Cove Point														33,000,000
Dominion Energy Virginia
Schedule of Equity Method Investments [Line Items]
Cash consideration from sale of noncontrolling interest				$ 120,000,000									215,000,000
Limited partnership interest sale transaction, proceeds received				$ 60,000,000						$ 108,000,000			$ 108,000,000
Percentage ownership in total units				50.00%						50.00%			50.00%
Initial fair value				$ 60,000,000						$ 107,000,000			$ 107,000,000
Amount of gain from sale										133,000,000		$ 23,000,000
Amount of gain from sale, after tax										$ 99,000,000		$ 16,000,000
Agreement entered date				2022-02
Cove Point
Schedule of Equity Method Investments [Line Items]
Distributions received from investment													$ 344,000,000	300,000,000	70,000,000
Percentage of noncontrolling limited partnership interest retained										50.00%			50.00%
Contributions to equity method affiliates													$ 0	0	0
Cove Point | Finite Lived Equity Method Investment Basis Difference
Schedule of Equity Method Investments [Line Items]
Equity method investment goodwill					221,000,000					$ 215,000,000			215,000,000	221,000,000
Cove Point | Cove Point
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investees															40,000,000
Cove Point | Cove Point | GT&S Transaction
Schedule of Equity Method Investments [Line Items]
Percentage of limited partner interest sold						25.00%
Percentage of noncontrolling limited partnership interest retained		50.00%				50.00%
Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investees													7,000,000	20,000,000	2,300,000,000
Net income (loss) from discontinued operations including noncontrolling interest													$ (7,000,000)	(20,000,000)	(2,300,000,000)
Percentage of noncontrolling limited partnership interest retained										53.00%			53.00%
Contributions to equity method affiliates													$ 3,000,000	965,000,000	107,000,000
Cost to acquire equity method investments																			$ 184,000,000
Equity in earnings (losses) on investments after tax													5,000,000	14,000,000	1,800,000,000
Atlantic Coast Pipeline | Revolving Credit Facility
Schedule of Equity Method Investments [Line Items]
Debt maximum borrowing capacity								$ 3,400,000,000										$ 1,900,000,000
Credit facility, maturity date								Oct. 31, 2021
Atlantic Coast Pipeline | Revolving Credit Facility | Financial Guarantee | Cumulative Effect, Period of Adoption, Adjustment
Schedule of Equity Method Investments [Line Items]
Retained earnings															48,000,000
Atlantic Coast Pipeline | Other Current Liabilities
Schedule of Equity Method Investments [Line Items]
Current liabilities					113,000,000					$ 114,000,000			114,000,000	113,000,000
Atlantic Coast Pipeline | DETI
Schedule of Equity Method Investments [Line Items]
Operating revenue from contracts with customers															$ 49,000,000
Atlantic Coast Pipeline | Pipelines | Jointly Owned Natural Gas Pipeline | Distribution
Schedule of Equity Method Investments [Line Items]
Length of natural gas pipeline (in miles) | mi									600
Duration of contract									20 years
Atlantic Coast Pipeline | Dominion Energy Gas Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage acquired																			5.00%
Percentage ownership in total units																			53.00%
Trading Securities
Schedule of Equity Method Investments [Line Items]
Rabbi trust securities					$ 122,000,000					$ 111,000,000			$ 111,000,000	$ 122,000,000
2019 Series A Corporate Units
Schedule of Equity Method Investments [Line Items]
Short-term deposit			$ 2,000,000,000.0
2019 Series A Corporate Units | Series A Preferred Stock
Schedule of Equity Method Investments [Line Items]
Redemption obligation			$ 1,600,000,000
Preferred stock dividend rate percentage			1.75%								1.75%
2019 Series A Corporate Units | Minimum
Schedule of Equity Method Investments [Line Items]
Short-term deposit			$ 1,600,000,000
2019 Series A Corporate Units | Maximum
Schedule of Equity Method Investments [Line Items]
Short-term deposit			$ 2,000,000,000.0

[1] Includes income tax expense (benefit) of $8 million, $188 million and $(204) million for the years ended December 31, 2022, 2021 and 2020, respectively.

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

[3] 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.

[4] See Note 3 for more information.