Significant Accounting Policies (Additional Information) (Details) - Virginia Electric and Power Company $ in Millions	9 Months Ended
Sep. 30, 2023 USD ($)
Significant Accounting Policies [Line Items]
Increase in asset retirement obligation	$ 510
Increase in regulatory assets	444
Increase in other deferred charges and other assets	$ 66

The increase (decrease) during the reporting period in the carrying amount of asset retirement obligations.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Name:	us-gaap_IncreaseDecreaseInAssetRetirementObligations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration