Acquisitions and Dispositions (Schedule of Results of Operations of Disposal Groups Reported As Discontinued Operations) (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Impairment of assets and other charges				$ 2,063		$ 195		$ 2,105
Asset retirement obligations				5,576	[1]	5,473	[1]	5,583
Income tax expense (benefit) from discontinued operations				$ 8		188		$ (204)
GT&S Transaction
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Loss associated with cash flow hedges of debt-related items		$ 237
Loss associated with cash flow hedges of debt-related items after tax		$ 178
Income tax expense (benefit) from discontinued operations						$ (17)
Q-Pipe Transaction
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Benefit associated with the termination	$ 25
Supply Header Project | GT&S Transaction
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Impairment of assets and other charges			$ 482
Asset impairment charges after tax			359
Atlantic Coast Pipeline Project | GT&S Transaction
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Asset retirement obligations			$ 75

[1] Includes $198 million and $368 million reported in other current liabilities for Dominion Energy at December 31, 2021 and 2022, respectively.