Income Taxes (Earliest Tax Year) (Detail)	12 Months Ended
	Dec. 31, 2024
Pennsylvania
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2012	[1]
Connecticut
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2021
Virginia
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2021	[2]
Utah
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2021	[1]
South Carolina
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2021

[1] Considered a major state for entities presented in discontinued operations.

[2] Considered a major state for Virginia Power’s operations.