Regulatory Assets and Liabilities (Schedule of Regulatory Liabilities) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Dec. 31, 2021
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		$ 830	$ 986	[1]
Regulatory liabilities-noncurrent		10,436	10,713	[1]
Total regulatory liabilities		11,266	11,699
Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		460	647	[2]
Regulatory liabilities-noncurrent		5,603	5,740	[2]
Total regulatory liabilities		$ 6,063	6,387
SCANA
Regulatory Liabilities [Line Items]
Estimation period of collection to be credited		11 years
Electric service customers over period		20 years
Provision for future cost of removal and AROs
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[3]	$ 181	181
Regulatory liabilities-noncurrent	[3]	2,346	2,331
Provision for future cost of removal and AROs | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[4]	154	154
Reserve for refunds and rate credits to electric utility customers
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[5]	243	420
Regulatory liabilities-noncurrent	[5]	413	448
Income taxes refundable through future rates
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[6]	150	153
Regulatory liabilities-noncurrent	[6]	4,164	4,260
Income taxes refundable through future rates | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[7]	63	63
Regulatory liabilities-noncurrent	[7]	2,305	2,335
Monetization of guarantee settlement
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[8]	67	67
Regulatory liabilities-noncurrent	[8]	$ 753	831
Electric service customers over period		20 years
Derivative Liabilities
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[9]	$ 103	69
Derivative Liabilities | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[9]	61	51
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		86	96
Regulatory liabilities-noncurrent		442	380
Other | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		50	73
Regulatory liabilities-noncurrent		208	179
Nuclear decommissioning trust
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[10]	2,016	2,158
Nuclear decommissioning trust | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[11]	2,016	2,158
Unrecognized Pension and Other Postretirement Benefit Costs
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[12]	188	200
Overrecovered Other Postretirement Benefit Costs
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[13]	114	105
Reserve for refunds to Virginia electric customers | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[14]	132	306
Regulatory liabilities-noncurrent	[14]	19	25
Provision For Future Cost Of Removal | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[4]	$ 1,055	$ 1,043

[1] Dominion Energy’s Consolidated Balance Sheet at December 31, 2021 has been derived from the audited Consolidated Balance Sheet at that date.

[2] Virginia Power’s Consolidated Balance Sheet at December 31, 2021 has been derived from the audited Consolidated Balance Sheet at that date.

[3] Rates charged to customers by Dominion Energy’s regulated businesses include a provision for the cost of future activities to remove assets that are expected to be incurred at the time of retirement.

[4] Rates charged to customers by Virginia Power's regulated businesses include a provision for the cost of future activities to remove assets that are expected to be incurred at the time of retirement.

[5] Reflects amounts previously collected from retail electric customers of DESC for the NND Project to be credited over an estimated 11-year period effective February 2019, in connection with the SCANA Merger Approval Order. See Notes 3 and 13 to the Consolidated Financial Statements in the Companies’ Annual Report on Form 10-K for the year ended December 31, 2021 for additional information. Also reflects amounts to be refunded to jurisdictional retail electric customers in Virginia associated with the settlement of the 2021 Triennial Review.  See Note 13 to the Consolidated Financial Statements in the Companies’ Annual Report on Form 10-K for the year ended December 31, 2021 for additional information.

[6] Amounts recorded to pass the effect of reduced income taxes from the 2017 Tax Reform Act to customers in future periods, which will primarily reverse at the weighted average tax rate that was used to build the reserves over the remaining book life of the property, net of amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC equity.

[7] Amounts recorded to pass the effect of reduced income taxes from the 2017 Tax Reform Act to customers in future periods, which will reverse at the weighted average tax rate that was used to build the reserves over the remaining book life of the property, net of amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC equity.

[8] Reflects amounts to be refunded to DESC electric service customers over a 20-year period ending in 2039 associated with the monetization of a bankruptcy settlement agreement.  See Note 3 to the Consolidated Financial Statements in the Companies’ Annual Report on Form 10-K for the year ended December 31, 2021 for additional information.

[9] For jurisdictions subject to cost-based rate regulation, changes in the fair value of derivative instruments result in the recognition of regulatory assets or regulatory liabilities as they are expected to be recovered from or refunded to customers.

[10] Primarily reflects a regulatory liability representing amounts collected from Virginia jurisdictional customers and placed in external trusts (including income, losses and changes in fair value thereon, as applicable) for the future decommissioning of Dominion Energy’s utility nuclear generation stations, in excess of the related AROs.

[11] Primarily reflects a regulatory liability representing amounts collected from Virginia jurisdictional customers and placed in external trusts (including income, losses and changes in fair value thereon) for the future decommissioning of Virginia Power’s utility nuclear generation stations, in excess of the related AROs. 

[12] Represents unrecognized pension and other postretirement employee benefit costs expected to be recovered or refunded through future rates generally over the expected remaining service period of plan participants by certain of Dominion Energy's rate-regulated subsidiaries.

[13] Reflects a regulatory liability for the collection of postretirement benefit costs allowed in rates in excess of expense incurred.

[14] Reflects amounts to be refunded to jurisdictional retail electric customers in Virginia associated with the settlement of the 2021 Triennial Review.  See Note 13 to the Consolidated Financial Statements in the Companies’ Annual Report on Form 10-K for the year ended December 31, 2021 for additional information.