Related-Party Transactions (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025		Mar. 31, 2024
Related Party Transaction [Line Items]
Services provided to affiliates		$ 4,076		$ 3,632
Virginia Electric and Power Company
Related Party Transaction [Line Items]
Commodity purchases from affiliates		366		198
Services provided to affiliates	[1]	2,765	[2]	2,489
Virginia Electric and Power Company | Related Party
Related Party Transaction [Line Items]
Services provided by affiliates	[3]	209		155
Services provided to affiliates		$ 4		$ 4

[1] See Note 19 for amounts attributable to affiliates.

[2] The significant expense categories and amounts in the segment information presented above align with the segment-level information that is regularly provided to Virginia Power’s CODM.

[3] Includes capitalized expenditures of $75 million and $53 million for the three months ended March 31, 2025 and 2024, respectively.