Regulatory Assets and Liabilities (Schedule of Regulatory Liabilities) (Detail) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		$ 749	$ 497	[1]
Regulatory liabilities-noncurrent		10,680	11,001	[1]
Total regulatory liabilities		11,429	11,498
Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		296	167	[2]
Regulatory liabilities-noncurrent		4,954	5,074	[2]
Total regulatory liabilities		5,250	5,241
Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[3]	37	41
Regulatory liabilities-noncurrent	[4]	820	800
Total regulatory liabilities		857	841
Provision for future cost of removal and AROs
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[5]	142	142
Regulatory liabilities-noncurrent	[5]	2,253	2,302
Provision for future cost of removal and AROs | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[6]	103	103
Provision for future cost of removal and AROs | Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[7]	18	18
Regulatory liabilities-noncurrent	[7]	93	95
Reserve for refunds and rate credits to electric utility customers
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[8]	134	143
Regulatory liabilities-noncurrent	[8]	588	656
Cost-of-service impact of 2017 Tax Reform Act
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[9]	35	4
Income taxes refundable through future rates
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[10]	140	77
Regulatory liabilities-noncurrent	[10]	4,988	5,088
Income taxes refundable through future rates | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[11]	54	54
Regulatory liabilities-noncurrent	[11]	2,425	2,438
Income taxes refundable through future rates | Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[11]	566	560
Monetization of guarantee settlement
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[12]	67	67
Regulatory liabilities-noncurrent	[12]	936	970
Deferred cost of fuel used in electric generation
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[13]	111	0
Deferred cost of fuel used in electric generation | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[14]	111	0
Regulatory liabilities-noncurrent	[14]	3	30
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		120	64
Regulatory liabilities-noncurrent		331	325
Other | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		28	10
Regulatory liabilities-noncurrent		161	81
Other | Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		13	15
Regulatory liabilities-noncurrent		10	12
Nuclear decommissioning trust
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[15]	1,372	1,471
Nuclear decommissioning trust | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[16]	1,372	1,471
Overrecovered Other Postretirement Benefit Costs
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[17]	212	189
Overrecovered Other Postretirement Benefit Costs | Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[17]	151	133
Provision For Future Cost Of Removal | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[6]	993	1,054
Overrecovered Gas Costs | Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[18]	$ 6	$ 8

[1] Dominion Energy’s Consolidated Balance Sheet at December 31, 2019 has been derived from the audited Consolidated Balance Sheet at that date.

[2] Virginia Power’s Consolidated Balance Sheet at December 31, 2019 has been derived from the audited Consolidated Balance Sheet at that date.

[3] Current regulatory liabilities are presented in other current liabilities in Dominion Energy Gas’ Consolidated Balance Sheets.

[4] Noncurrent regulatory liabilities are presented in other deferred credits and other liabilities in Dominion Energy Gas’ Consolidated Balance Sheets.

[5] 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.

[6] 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.

[7] Rates charged to customers by Dominion Energy Gas' 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.

[8] 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, 2019 for more information.

[9] Balance refundable to customers related to the decrease in revenue requirements for recovery of income taxes at the Companies’ regulated electric generation and electric and natural gas distribution operations. 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, 2019 for more information.

[10] 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.

[11] 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.

[12] 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, 2019 for more information.

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

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

[15] 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.

[16] 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.

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

[18] Reflects unrecovered or overrecovered gas costs at regulated gas operations, which are recovered or refunded through filings with FERC.