Derivatives and Hedge Accounting Activities (Gains and Losses on Derivatives in Cash Flow Hedging Relationships) (Detail) - Cash Flow Hedges - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives	[1]	$ (1)	$ 89	$ 21
Amount of Gain (Loss) Reclassified From AOCI to Income		(43)	(57)	(61)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2]	5	855	135
Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives	[1]	(1)	80	17
Amount of Gain (Loss) Reclassified From AOCI to Income		(1)	(2)	(3)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2]	4	854	130
Commodity
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified From AOCI to Income	[3]			(1)
Interest Rate
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives	[1],[4]	(1)	89	21
Amount of Gain (Loss) Reclassified From AOCI to Income	[4]	(43)	(57)	(60)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2],[4]	5	855	135
Interest Rate | Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives	[1],[4]	(1)	80	17
Amount of Gain (Loss) Reclassified From AOCI to Income	[4]	(1)	(2)	(3)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2],[4]	$ 4	$ 854	$ 130

[1] Amounts deferred into AOCI have no associated effect in the Companies’ Consolidated Statements of Income.

[2] Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in the Companies’ Consolidated Statements of Income.

[3] Amounts recorded in Dominion Energy’s Consolidated Statements of Income are classified in purchased gas.

[4] Amounts recorded in the Companies’ Consolidated Statements of Income are classified in interest and related charges