Significant Accounting Policies (Reconciliation of Total Cash, Restricted Cash and Equivalents) (Detail) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	[1]	$ 217	$ 153	$ 283	$ 179
Cash and cash equivalents		184	119
Restricted cash and equivalents	[2],[3]	84	188	125	68
Restricted cash and equivalents		4	2	3	3
Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows		301	341	408	247
Virginia Electric and Power Company
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents		90	22	26	35
Restricted cash and equivalents	[3]		2
Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows		$ 90	$ 24	$ 26	$ 35

[1] At December 31, 2023, 2022, 2021 and 2020, Dominion Energy had $33 million, $34 million, $49 million and $21 million, respectively, of cash and cash equivalents included in current assets held for sale.

[2] At December 31, 2023, 2022, 2021 and 2020, Dominion Energy had $4 million, $2 million, $3 million and $3 million, respectively, of restricted cash and equivalents included in current assets held for sale with the remaining balances presented within other current assets in Dominion Energy’s Consolidated Balance Sheets.

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