Significant Accounting Policies (Reconciliation of Total Cash, Restricted Cash and Equivalents) (Detail) - USD ($) $ in Millions		Jun. 30, 2024	Dec. 31, 2023		Jun. 30, 2023	Dec. 31, 2022
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	[1]	$ 140	$ 217		$ 137	$ 153
Cash and cash equivalents		139	184	[2]
Restricted cash and equivalents	[3],[4]	67	84		178	188
Restricted cash and equivalents			4		3	2
Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows		207	301		315	341
Virginia Electric and Power Company
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents		41	90	[5]	19	22
Restricted cash and equivalents	[4],[6]	45				2
Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows		$ 86	$ 90		$ 19	$ 24

[1] At June 30, 2024, June 30, 2023, December 31, 2023 and December 31, 2022, Dominion Energy had $1 million, $29 million, $33 million and $34 million, respectively, of cash and cash equivalents included in current assets held for sale.

[2] Dominion Energy’s Consolidated Balance Sheet at December 31, 2023 has been derived from the audited Consolidated Balance Sheet at that date.

[3] At June 30, 2024, June 30, 2023, December 31, 2023 and December 31, 2022, Dominion Energy had less than $1 million, $3 million, $4 million and $2 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.

[4] Includes $40 million attributable to VIEs at June 30, 2024.

[5] Virginia Power’s Consolidated Balance Sheet at December 31, 2023 has been derived from the audited Consolidated Balance Sheet at that date.

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