Preferred Stock (Narrative) (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Jun. 30, 2022	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 15, 2024	Jun. 30, 2019	Jun. 14, 2019
Class of Stock [Line Items]
Preferred stock shares authorized			20,000,000
Total Preferred Stock		$ 2,387,000,000	$ 2,387,000,000	$ 2,387,000,000
Dividend stock			65,000,000	$ 17,000,000
Preferred stock, redemption price per share		$ 1,020		$ 1,020
Forecast
Class of Stock [Line Items]
Preferred stock, redemption price per share					$ 1,000
2019 Series A Corporate Units
Class of Stock [Line Items]
Debt Instrument, Face Amount							$ 1,600,000,000
Percentage of interest in undivided beneficial ownership						10.00%
2019 Series A Corporate Units | Forecast | Maximum
Class of Stock [Line Items]
Shares to be issued under purchase contracts	21,800,000
2019 Series A Corporate Units | Common Stock
Class of Stock [Line Items]
Purchase price to be paid under stock purchase contracts							$ 100
Dominion Energy
Class of Stock [Line Items]
Dividend rate percentage		2.993%
Dividend stock			$ 37,000,000	$ 2,000,000
Dominion Energy | Preferred Class A
Class of Stock [Line Items]
Preferred stock shares issued		2,400,000	2,400,000	2,400,000
Preferred stock shares outstanding		2,400,000	2,400,000	2,400,000
Dominion Energy | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock shares issued		1,600,000	1,600,000	1,600,000
Preferred stock shares outstanding		1,600,000	1,600,000	1,600,000
Dominion Energy | Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock shares authorized		800,000		800,000
Preferred stock shares issued		800,000	800,000	800,000
Preferred stock shares outstanding		800,000	800,000	800,000
Total Preferred Stock		$ 791,000,000		$ 791,000,000
Issuance of costs		9,000,000
Preferred stock liquidation value		$ 1,000		$ 1,000
Dividend rate percentage		4.65%
Dividends per share			$ 46.50	$ 1.9375
DESC
Class of Stock [Line Items]
Preferred stock shares authorized			20,000,000
SCANA
Class of Stock [Line Items]
Preferred Stock Held By SCANA		1,000	1,000	1,000
Virginia Electric and Power Company
Class of Stock [Line Items]
Preferred stock shares authorized			10,000,000
Preferred stock shares issued		0	0	0
Preferred stock shares outstanding		0	0	0
Liquidation preference			$ 100