Derivatives and Hedge Accounting Activities (Gains and Losses on Derivatives in Cash Flow Hedging Relationships) (Detail) - Cash Flow Hedges - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives	[1]	$ 33	$ 52
Amount of Gain (Loss) Reclassified From AOCI to Income		(14)	(17)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2]	279	408
Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives	[3]	26	43
Amount of Gain (Loss) Reclassified From AOCI to Income		(1)	(1)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[4]	279	407
Interest Rate Contract
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives	[1],[5]	33	52
Amount of Gain (Loss) Reclassified From AOCI to Income	[5]	(14)	(16)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2],[5]	279	408
Interest Rate Contract | Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives	[3],[6]	26	43
Amount of Gain (Loss) Reclassified From AOCI to Income	[6]	(1)	(1)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[4],[6]	$ 279	407
Commodity Contract
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified From AOCI to Income	[7]		$ (1)

[1] Amounts deferred into AOCI have no associated effect in Dominion Energy’s 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 Dominion Energy’s Consolidated Statements of Income.

[3] Amounts deferred into AOCI have no associated effect in Virginia Power’s Consolidated Statements of Income.

[4] Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Virginia Power’s Consolidated Statements of Income.

[5] Amounts recorded in Dominion Energy’s Consolidated Statement of Income are classified in interest and related charges.

[6] Amounts recorded in Virginia Power’s Consolidated Statements of Income are classified in interest and related charges.

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