Employee Benefit Plans (Narrative) (Detail) - USD ($)		1 Months Ended		3 Months Ended					12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated benefit obligation		$ 10,200,000,000	$ 10,600,000,000	$ 10,200,000,000	$ 10,600,000,000					$ 10,200,000,000	$ 10,600,000,000
Contributions to qualified defined benefit pension plans, shares												6,100,000
Defined contribution plan, employer matching contributions										65,000,000	67,000,000	$ 69,000,000
Discontinued Operations
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost										$ 1,000,000	13,000,000	16,000,000
Common and Preferred Stocks
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages		27.00%		27.00%						27.00%
Non-U.S. Equity
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages		18.00%		18.00%						18.00%
Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages		32.00%		32.00%						32.00%
Real Estate Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages		3.00%		3.00%						3.00%
Other than Securities Investment
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages		20.00%		20.00%						20.00%
Common Stock
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to qualified defined benefit pension plans												499,000,000
Series C Preferred Stock
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Issued to qualified defined benefit pension plans, shares		250,000
Virginia Electric and Power Company
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amounts due to Dominion		$ 121,000,000	266,000,000	$ 121,000,000	266,000,000					$ 121,000,000	266,000,000
Defined contribution plan, employer matching contributions										20,000,000	19,000,000	20,000,000
BHE
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution to voluntary employees beneficiary association												12,000,000
Pension Plans and Post Retirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual return (loss) on pension and other postretirement plan assets										1,500,000,000	1,900,000,000
Expected return on pension and other postretirement plan assets										1,000,000,000.0	933,000,000
Curtailment resulted in a decrease in the pension benefit obligation				26,000,000
Increase to net periodic benefit cost (credit)				$ 2,000,000
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual return (loss) on pension and other postretirement plan assets										1,202,000,000	1,602,000,000
Expected return on pension and other postretirement plan assets										834,000,000	777,000,000	708,000,000
Increase to net periodic benefit cost (credit)										(144,000,000)	(32,000,000)	93,000,000
Increase (decrease) in fair value of plan assets							$ 51,000,000	$ 671,000,000
Actuarial gains (losses) from increase decrease in discount rate										413,000,000	(1,000,000,000.0)
Contributions to qualified defined benefit pension plans			250,000,000							284,000,000	278,000,000	520,000,000
Service cost										170,000,000	173,000,000	162,000,000
Pension Benefits | Series C Preferred Stock
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to qualified defined benefit pension plans		$ 250,000,000
Pension Benefits | Virginia Electric and Power Company | Amounts Associated With Dominion Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Payment made to Dominion										175,000,000	313,000,000	0
Amounts due to Dominion			$ 151,000,000		$ 151,000,000						151,000,000
Pension Benefits | Virginia Electric and Power Company | Other Operations and Maintenance
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Increase to net periodic benefit cost (credit)										$ 86,000,000	$ 118,000,000	152,000,000
Pension Benefits | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate percentage		3.06%	2.73%	3.06%	2.73%			4.07%		3.06%	2.73%
Pension Benefits | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate percentage		3.19%	2.95%	3.19%	2.95%			4.10%		3.19%	2.95%
Pension Benefits | BHE
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Increase to net periodic benefit cost (credit)											$ (4,000,000)
Remeasurement resulted in increase in pension benefit obligation						$ 497,000,000
Increase (decrease) in fair value of plan assets						$ (87,000,000)
Pension Benefits | BHE | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate percentage			3.11%		3.11%						3.11%
Pension Benefits | BHE | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate percentage			3.16%		3.16%						3.16%
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual return (loss) on pension and other postretirement plan assets										$ 294,000,000	$ 300,000,000
Expected return on pension and other postretirement plan assets										173,000,000	156,000,000	140,000,000
Increase to net periodic benefit cost (credit)										$ (140,000,000)	$ (172,000,000)	$ (46,000,000)
Increase (decrease) in fair value of plan assets								$ 156,000,000
Health care cost trend rate	[1]	6.25%	6.25%	6.25%	6.25%					6.25%	6.25%
Health care cost trend decreased rate	[1]	5.00%	5.00%	5.00%	5.00%					5.00%	5.00%	5.00%
Actuarial gains (losses) from increase decrease in discount rate										$ 161,000,000	$ (149,000,000)
Actuarial gain from completed experience study and update to healthcare claim assumptions											85,000,000
Contributions to qualified defined benefit pension plans											13,000,000
Contribution to voluntary employees beneficiary association										0
Service cost										25,000,000	28,000,000	$ 26,000,000
Other Postretirement Benefits | Virginia Electric and Power Company
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution to voluntary employees beneficiary association										0	0	0
Other Postretirement Benefits | Virginia Electric and Power Company | Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution to voluntary employees beneficiary association									$ 0
Other Postretirement Benefits | Virginia Electric and Power Company | Other Operations and Maintenance | Dominion Energy Retiree Health And Welfare Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Increase to net periodic benefit cost (credit)										$ (72,000,000)	$ (58,000,000)	$ (27,000,000)
Other Postretirement Benefits | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate percentage		3.04%	2.69%	3.04%	2.69%			4.05%		3.04%	2.69%
Health care cost trend rate	[1]											6.50%
Other Postretirement Benefits | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate percentage		3.11%	2.80%	3.11%	2.80%			4.08%		3.11%	2.80%
Health care cost trend rate	[1]											6.60%
Other Postretirement Benefits | BHE
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Increase (decrease) in fair value of plan assets					$ (25,000,000)
Increase in accumulated postretirement benefit obligation					$ 16,000,000
Health care cost trend rate			6.25%		6.25%						6.25%
Health care cost trend decreased rate			5.00%		5.00%						5.00%
Other Postretirement Benefits | BHE | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate percentage			3.07%		3.07%						3.07%
Other Postretirement Benefits | BHE | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate percentage			3.11%		3.11%						3.11%
Voluntary Retirement Program
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Remeasurement resulted in increase in pension benefit obligation							$ 37,000,000	$ 484,000,000
Discount rate percentage							3.57%
Increase in accumulated postretirement benefit obligation								$ 101,000,000
Voluntary retirement program related charges												$ 427,000,000
Voluntary retirement program related charges net of tax												319,000,000
Voluntary Retirement Program | Other Operations and Maintenance
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntary retirement program related charges												251,000,000
Voluntary Retirement Program | Other Taxes
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntary retirement program related charges												21,000,000
Voluntary Retirement Program | Other Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntary retirement program related charges												111,000,000
Voluntary Retirement Program | Net Income Including Noncontrolling Interest From Discontinued Operations
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntary retirement program related charges												44,000,000
Voluntary Retirement Program | Virginia Electric and Power Company
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntary retirement program related charges												198,000,000
Voluntary retirement program related charges net of tax												146,000,000
Voluntary Retirement Program | Virginia Electric and Power Company | Other Operations and Maintenance
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntary retirement program related charges												190,000,000
Voluntary Retirement Program | Virginia Electric and Power Company | Other Taxes
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Voluntary retirement program related charges												$ 8,000,000

[1] Assumptions used to determine net periodic cost for the following year.