Regulatory Assets and Liabilities (Schedule of Regulatory Assets) (Detail) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2022	Dec. 31, 2021
Regulatory Assets [Line Items]
Regulatory assets-current		$ 1,863	$ 1,492	[1]
Regulatory assets-noncurrent		8,371	8,643	[1]
Total regulatory assets		$ 10,234	10,135
Weighted Average
Regulatory Assets [Line Items]
Weighted average useful life		27 years
SCANA
Regulatory Assets [Line Items]
Electric service customers over period		20 years
Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current		$ 1,129	850	[2]
Regulatory assets-noncurrent		3,916	4,130	[2]
Total regulatory assets		$ 5,045	4,980
Virginia Electric and Power Company | Weighted Average
Regulatory Assets [Line Items]
Weighted average useful life		24 years
Deferred cost of fuel used in electric generation
Regulatory Assets [Line Items]
Regulatory assets-current	[3]	$ 505	251
Regulatory assets-noncurrent	[3]	835	409
Deferred cost of fuel used in electric generation | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[4]	294	131
Regulatory assets-noncurrent	[4]	835	409
Deferred project costs and DSM programs for gas utilities
Regulatory Assets [Line Items]
Regulatory assets-current	[5]	85	53
Unrecovered gas costs
Regulatory Assets [Line Items]
Regulatory assets-current	[6]	119	191
Deferred rider costs for Virginia electric utility
Regulatory Assets [Line Items]
Regulatory assets-current	[7]	106	72
Regulatory assets-noncurrent	[7]	351	489
Ash pond and landfill closure costs
Regulatory Assets [Line Items]
Regulatory assets-current	[8]	108	193
Regulatory assets-noncurrent	[8]	$ 2,262	2,223
Regulatory assets expected collection period commencing year		2021
Ash pond and landfill closure costs | Maximum
Regulatory Assets [Line Items]
Regulatory assets amounts expected collection period		18 years
Ash pond and landfill closure costs | Minimum
Regulatory Assets [Line Items]
Regulatory assets amounts expected collection period		15 years
Ash pond and landfill closure costs | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[9]	$ 108	193
Regulatory assets-noncurrent	[9]	$ 2,259	2,223
Regulatory assets expected collection period commencing year		2021
Ash pond and landfill closure costs | Virginia Electric and Power Company | Maximum
Regulatory Assets [Line Items]
Regulatory assets amounts expected collection period		18 years
Ash pond and landfill closure costs | Virginia Electric and Power Company | Minimum
Regulatory Assets [Line Items]
Regulatory assets amounts expected collection period		15 years
Deferred nuclear refueling outage costs
Regulatory Assets [Line Items]
Regulatory assets-current	[10]	$ 63	79
Deferred nuclear refueling outage costs | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[11]	63	79
NND Project Costs
Regulatory Assets [Line Items]
Regulatory assets-current	[12]	138	138
Regulatory assets-noncurrent	[12]	2,157	2,226
Deferred early plant retirement charges
Regulatory Assets [Line Items]
Regulatory assets-current	[13]	226	226
Regulatory assets-noncurrent	[13]	113	226
Deferred early plant retirement charges | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[14]	226	226
Regulatory assets-noncurrent	[14]	113	226
Derivatives
Regulatory Assets [Line Items]
Regulatory assets-current	[15]	278	112
Regulatory assets-noncurrent	[15]	325	35
Derivatives | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[15]	272	105
Regulatory assets-noncurrent	[15]	213	34
Other
Regulatory Assets [Line Items]
Regulatory assets-current		235	177
Regulatory assets-noncurrent		541	584
Other | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current		60	44
Regulatory assets-noncurrent		145	145
Unrecognized Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[16]	564	548
Deferred project costs for gas utilities
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[5]	667	675
Interest rate hedges
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[17]	170	899
Interest rate hedges | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[18]		604
AROs and related funding
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[19]	$ 386	329
Amortization period for deferred costs		105 years
Deferred Project Costs | Maximum
Regulatory Assets [Line Items]
Amortization period for deferred costs		18 months
Deferred Project Costs | Virginia Electric and Power Company | Maximum
Regulatory Assets [Line Items]
Amortization period for deferred costs		18 months
Cost of Fuel Filing
Regulatory Assets [Line Items]
Increase/decrease in Regulatory Assets/Liabilities		$ 66
Deferred rider costs | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[20]	106	72
Regulatory assets-noncurrent	[20]	$ 351	$ 489

[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] Reflects deferred fuel expenses for the Virginia, North Carolina and South Carolina jurisdictions of Dominion Energy’s electric generation operations. Reflects a $66 million reduction recorded in the first quarter of 2022 from the application of a portion of the monetization of guarantee settlement previously reflected as regulatory liabilities associated with the approval of DESC’s cost of fuel proceedings. See Note 13 for additional information

[4] Reflects deferred fuel expenses for the Virginia and North Carolina jurisdictions of Virginia Power’s generation operations. See Note 13 for additional information.

[5] Primarily reflects amounts expected to be collected from or owed to gas customers in Dominion Energy’s service territories associated with current and prospective rider projects, including CEP, PIR and pipeline integrity management. See Note 13 for additional information

[6] Reflects unrecovered gas costs at regulated gas operations, which are recovered through filings with the applicable regulatory authority.

[7] Reflects deferrals under Virginia Power’s electric transmission FERC formula rate and the deferral of costs associated with certain current and prospective rider projects. See Note 13 for additional information.

[8] Primarily reflects legislation enacted in Virginia in 2019, which requires any CCR asset located at certain Virginia Power stations to be closed by removing the CCR to an approved landfill or through beneficial reuse. These deferred costs are expected to be collected over a period between 15 and 18 years commencing December 2021 through Rider CCR. Virginia Power is entitled to collect carrying costs on uncollected  expenditures once expenditures have been made. See Note 13 for additional information.

[9] Primarily reflects legislation enacted in Virginia in 2019, which requires any CCR asset located at certain Virginia Power stations to be closed by removing the CCR to an approved landfill or through beneficial reuse. These deferred costs are expected to be collected over a period between 15 and 18 years commencing December 2021 through Rider CCR. Virginia Power is entitled to collect carrying costs on uncollected expenditures once expenditures have been made. See Note 13 for additional information.

[10] Legislation enacted in Virginia in April 2014 requires Virginia Power to defer operation and maintenance costs incurred in connection with the refueling of any nuclear-powered generating plant. These deferred costs will be amortized over the refueling cycle, not to exceed 18 months.

[11] Legislation enacted in Virginia in April 2014 requires Virginia Power to defer operation and maintenance costs incurred in connection with the refueling of any nuclear-powered generating plant. These deferred costs will be amortized over the refueling cycle, not to exceed 18 months.

[12] Reflects expenditures by DESC associated with the NND Project, which pursuant to the SCANA Merger Approval Order, will be recovered from DESC electric service customers over a 20-year period ending in 2039. 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.

[13] Reflects amounts from the early retirements of certain coal- and oil-fired generating units to be amortized through 2023 in accordance 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.

[14] Reflects amounts from the early retirements of certain coal- and oil-fired generating units to be amortized through 2023 in accordance 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.

[15] Represents changes in the fair value of derivatives, excluding separately presented interest rate hedges, that following settlement are expected to be recovered from or refunded to customers.

[16] 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.

[17] Reflects interest rate hedges recoverable from or refundable to customers. Certain of these instruments are settled and any related payments are being amortized into interest expense over the life of the related debt, which has a weighted-average useful life of approximately 27 years as of June 30, 2022. 

[18] Reflects interest rate hedges recoverable from or refundable to customers. Certain of these instruments are settled and any related payments are being amortized into interest expense over the life of the related debt, which has a weighted-average useful life of approximately 24 years as of June 30, 2022.

[19] Represents deferred depreciation and accretion expense related to legal obligations associated with the future retirement of generation, transmission and distribution properties. The AROs primarily relate to DESC’s electric generating facilities, including Summer, and are expected to be recovered over the related property lives and periods of decommissioning which may range up to approximately 105 years.

[20] Reflects deferrals under Virginia Power’s electric transmission FERC formula rate and the deferral of costs associated with certain current and prospective rider projects. See Note 13 for additional information.