Significant Financing Transactions (Commercial Paper, Bank Loans and Letters of Credit Outstanding) (Detail)	Mar. 31, 2025 USD ($)
Line of Credit Facility [Line Items]
Facility Limit	$ 6,000,000,000	[1]
Outstanding Commercial Paper	1,638,000,000	[1]
Outstanding Letters of Credit	7,000,000	[1]
Facility Capacity Available	4,355,000,000	[1]
Virginia Electric and Power Company
Line of Credit Facility [Line Items]
Facility Limit	6,000,000,000
Outstanding Commercial Paper	244,000,000
Outstanding Letters of Credit	$ 7,000,000

[1] This credit facility, as amended in April 2025, matures in April 2030, with the potential to be extended by the borrowers to April 2032, and can be used by the borrowers under the credit facility to support bank borrowings and the issuance of commercial paper, as well as to support up to a combined $3.0 billion of letters of credit