Regulatory Assets and Liabilities (Schedule of Regulatory Assets) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Regulatory Assets [Line Items]
Regulatory assets-current		$ 1,492	$ 699
Regulatory assets-noncurrent		8,643	9,133
Total regulatory assets		10,135	9,832
Dominion Energy South Carolina Inc
Regulatory Assets [Line Items]
Write off of regulatory asset		237
Write off of regulatory asset after tax		178
Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current		850	295
Regulatory assets-noncurrent		4,130	3,509
Total regulatory assets		$ 4,980	3,804
SCANA
Regulatory Assets [Line Items]
Electric service customers over period		20 years
Weighted Average
Regulatory Assets [Line Items]
Weighted average useful life		27 years
Weighted Average | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Weighted average useful life		25 years
Deferred cost of fuel used in electric generation
Regulatory Assets [Line Items]
Regulatory assets-current	[1]	$ 251
Regulatory assets-noncurrent	[1]	409
Deferred cost of fuel used in electric generation | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[2]	131
Regulatory assets-noncurrent	[2]	409
Deferred project costs and DSM programs for gas utilities
Regulatory Assets [Line Items]
Regulatory assets-current	[3]	53	35
Unrecovered Gas Costs
Regulatory Assets [Line Items]
Regulatory assets-current	[4]	191	78
Deferred rider costs for Virginia electric utility
Regulatory Assets [Line Items]
Regulatory assets-current	[5]	72	98
Regulatory assets-noncurrent	[5]	489	311
Ashpond and landfill closure costs
Regulatory Assets [Line Items]
Regulatory assets-current	[6]	193
Ashpond and landfill closure costs | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[7]	193
Deferred Nuclear Refueling Outage Costs
Regulatory Assets [Line Items]
Regulatory assets-current	[8]	79	53
Deferred Nuclear Refueling Outage Costs | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[8]	79	53
NND Project Costs
Regulatory Assets [Line Items]
Regulatory assets-current	[9]	138	138
Regulatory assets-noncurrent	[9]	2,226	2,364
PJM transmission rates
Regulatory Assets [Line Items]
Regulatory assets-current	[10]	7	71
PJM transmission rates | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[11]	7	71
Deferred early plant retirement charges
Regulatory Assets [Line Items]
Regulatory assets-current	[12]	226
Regulatory assets-noncurrent	[12]	226
Deferred early plant retirement charges | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[13]	226
Regulatory assets-noncurrent	[13]	226
Other
Regulatory Assets [Line Items]
Regulatory assets-current		170	193
Regulatory assets-noncurrent		609	544
Other | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current		37	33
Regulatory assets-noncurrent		179	164
Derivatives
Regulatory Assets [Line Items]
Regulatory assets-current	[14]	112	33
Derivatives | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[14]	105	40
Unrecognized Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[15]	548	1,363
Deferred Project Costs For Gas Utilities
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[3]	675	632
Interest rate hedges
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[16]	899	1,042
Interest rate hedges | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[17]	604	733
AROs and related funding
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[18]	$ 329	331
Amortization period for deferred costs		105 years
Cost of reacquired debt
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[19]	$ 10	245
Ash pond and landfill closure costs
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[6]	$ 2,223	2,301
Regulatory assets expected collection period commencing year		2021
Ash pond and landfill closure costs | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[6]	$ 2,223	2,301
Regulatory assets expected collection period commencing year		2021
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 | Minimum | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets amounts expected collection period		15 years
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 | Maximum | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets amounts expected collection period		18 years
Deferred Project Costs | Maximum
Regulatory Assets [Line Items]
Amortization period for deferred costs		18 months
Deferred Project Costs | Maximum | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Amortization period for deferred costs		18 months
Deferred rider costs | Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current	[5]	$ 72	98
Regulatory assets-noncurrent	[5]	$ 489	$ 311

[1] Reflects deferred fuel expenses for the Virginia, North Carolina and South Carolina jurisdictions of Dominion Energy’s electric generation operations.

[2] Reflects deferred fuel expenses for the Virginia and North Carolina jurisdictions of Virginia Power’s generation operations

[3] 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 more information

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

[5] 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 more information

[6] 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.

[7] 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.

[8] 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

[9] 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 for more information

[10] Reflects current portion of amounts to be recovered through retail rates in Virginia for payments Virginia Power expects to make to PJM through 2026 under the terms of a FERC settlement agreement in May 2018 resolving a PJM cost allocation matter.‌

[11] Reflects current portion of amounts to be recovered through retail rates in Virginia for payments Virginia Power expects to make to PJM through 2026 under the terms of a FERC settlement agreement in May 2018 resolving a PJM cost allocation matter.

[12] 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 for additional information

[13] Reflects amounts from the early retirement 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 for more information

[14] 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

[15] 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

[16] 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 December 31, 2021

[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 25 years as of December 31, 2021

[18] 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

[19] In 2021, DESC recorded a charge of $237 million ($178 million after-tax) in impairment of assets and other charges, reflected in the Corporate and Other segment, to write-off the balance of a regulatory asset that is no longer probable of recovery under the settlement agreement approved in DESC’s retail electric base rate case.  See Note 13 for more information.