Regulatory Matters - Schedule of Additional Significant Riders Associated with Virginia Power Projects (Parenthetical) (Detail) $ in Millions		1 Months Ended	3 Months Ended
		Jul. 31, 2023 USD ($)	Mar. 31, 2024 USD ($) Project Agreement
Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Additional total revenue requirement			$ 120
Rider T1 | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement	[1]		1,170
Rider T1 | Operating Segments | Virginia Electric and Power Company | Virginia Regulation
Public Utilities, General Disclosures [Line Items]
Total revenue requirement			638
Rider T1 | Operating Segments | Virginia Electric and Power Company | Virginia Regulation | Transmission Component Of Virginia Powers
Public Utilities, General Disclosures [Line Items]
Total revenue requirement			$ 532
Rider CE
Public Utilities, General Disclosures [Line Items]
Public utilities number of power purchase agreements | Agreement			13
Rider CE | Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Total revenue requirement	[1],[2]		$ 133
Public utilities number of solar generation projects | Project			4
Base Rate Case | Virginia Electric and Power Company | Virginia Regulation
Public Utilities, General Disclosures [Line Items]
Total revenue requirement		$ 350

[1] In addition, Virginia Power has various riders associated with other projects with an aggregate total annual revenue requirement of approximately $120 million as of March 31, 2024.

[2] The Virginia Commission approved four solar generation projects and 13 power purchase agreements in addition to previously approved Rider CE projects. In addition, the approved total revenue requirement includes amounts which had previously been collected under a separate rider.