Asset Impairment Charges After Tax

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- Definition

Asset retirement obligation liabilities incurred after tax.

+ References

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- Definition

Costs incurred asset retirement obligation incurred after tax.

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- Definition

Percentage of equity interests expected to be sold.

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- Definition

[Line Items] for Significant Accounting Policies [Table]

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- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
-Paragraph 4
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- Definition

Amount of asset retirement obligations incurred during the period.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
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Amount of increase (decrease) in asset retirement obligations.

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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of asset retirement obligations (ARO) costs incurred (whether capitalized or charged to expense) during the period.

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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- Definition

Amount of increase (decrease) of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Significant Accounting Policies (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended						6 Months Ended	9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Aug. 31, 2021
Significant Accounting Policies [Line Items]
Impairment of assets and other charges (benefits)	$ (222)			$ 1,151				$ 194	$ 1,963
Asset retirement obligations decrease								(252)
Property, plant and equipment, net, decrease								(173)
Other Operations and Maintenance
Significant Accounting Policies [Line Items]
Asset retirement obligation, liabilities incurred							$ 44
Asset retirement obligation, liabilities incurred after tax							$ 35
Virginia Electric and Power Company
Significant Accounting Policies [Line Items]
Impairment of assets and other charges (benefits)	$ (230)			$ 200				$ (269)	$ 1,008
Virginia Electric and Power Company \| Impairment of Assets and Other Charges
Significant Accounting Policies [Line Items]
Impairment of assets and other charges (benefits)		$ 76	$ 127			$ 754
Asset impairment charges after tax		$ 56				$ 561
Virginia Electric and Power Company \| Electric Generation Facilities \| Impairment of Assets and Other Charges
Significant Accounting Policies [Line Items]
Charges recorded with dismantling					$ 30
Charges recorded with dismantling after tax					$ 22
Cove Point \| Brookfield
Significant Accounting Policies [Line Items]
Percentage of equity interest sold to noncontrolling interest owners	25.00%							25.00%
Four Brothers and Three Cedars
Significant Accounting Policies [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	50.00%							50.00%
Four Brothers and Three Cedars \| Dominion Energy Midstream Partners, LP \| Terra Nova Renewable Partners \| Nonregulated Solar Projects
Significant Accounting Policies [Line Items]
Percentage of equity interest sold to noncontrolling interest owners	33.00%							33.00%
Four Brothers and Three Cedars \| Dominion Energy Midstream Partners, LP \| Clearway
Significant Accounting Policies [Line Items]
Percentage of equity interests expected to be sold										50.00%