Investments (Investments Under Equity Method of Accounting) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Investment in equity method affiliates		$ 311	[1]	$ 3,012
Cove Point
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	[2]	50.00%
Investment in equity method affiliates		$ 0		2,673	[3]
Description		LNG import/export and storage facility
Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		53.00%
Investment in equity method affiliates	[3]	$ 0		0
Description		Gas transmission system
Align RNG, LLC
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
Investment in equity method affiliates		$ 80		103
Description		Renewable natural gas
Dominion Energy Virginia
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
Investment in equity method affiliates		$ 172		176
Description		Military electric and gas
Other Investment
Schedule of Equity Method Investments [Line Items]
Investment in equity method affiliates		$ 59		$ 60	[1]
Ownership%		various

[1] Dominion Energy’s Consolidated Balance Sheets includes balances presented in current assets held for sale of $43 million and noncurrent assets held for sale of $43 million, at December 31, 2023 and 2022, respectively.

[2] Dominion Energy’s sold its remaining 50% noncontrolling limited partnership interest in September 2023. See discussion below. Presented in noncurrent assets held for sale in Dominion Energy’s Consolidated Balance Sheets at December 31, 2022.

[3] Dominion Energy’s Consolidated Balance Sheets include a liability associated with its investment in Atlantic Coast Pipeline of $4 million and $114 million at December 31, 2023 and 2022, respectively, presented in other current liabilities. See discussion below for additional information.