Significant Accounting Policies (Reconciliation of Total Cash, Restricted Cash and Equivalents) (Detail) - USD ($) $ in Millions		Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022	Dec. 31, 2021
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	[1]	$ 310		$ 217		$ 153	$ 283
Cash and cash equivalents	[2]	310		184
Restricted cash and equivalents	[3],[4]	55		84		188	125
Restricted cash and equivalents				4		2	3
Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows		365		301		341	408
Virginia Electric and Power Company
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents		160	[5]	90	[5]	22	26
Restricted cash and equivalents	[4],[6]	46				2
Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows		$ 206		$ 90		$ 24	$ 26

[1] At December 31, 2023, 2022 and 2021, Dominion Energy had $33 million, $34 million and $49 million, respectively, of cash and cash equivalents included in assets held for sale.

[2] See Note 16 for amounts attributable to VIEs.

[3] At December 31, 2023, 2022 and 2021, Dominion Energy had $4 million, $2 million and $3 million, respectively, of restricted cash and equivalents included in assets held for sale with the remaining balances presented within other current assets in Dominion Energy’s Consolidated Balance Sheets.

[4] Includes $41 million at VPFS attributable to VIEs at December 31, 2024.

[5] See Note 16 for amounts attributable to VIEs.

[6] Restricted cash and equivalents balances are presented within other current assets in Virginia Power’s Consolidated Balance Sheets.