Significant Accounting Policies (Reconciliation of Total Cash, Restricted Cash and Equivalents) (Detail) - USD ($) $ in Millions		Mar. 31, 2025		Dec. 31, 2024		Mar. 31, 2024	Dec. 31, 2023
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	[1]	$ 355		$ 310		$ 306	$ 217	[2]
Cash and cash equivalents	[3]	355		310	[4]
Restricted cash and equivalents	[2],[5],[6]	122		55		30	84
Restricted cash and equivalents						4	4
Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows		477		365		336	301
Virginia Electric and Power Company
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents		180	[7]	160	[7],[8]	119	90
Restricted cash and equivalents	[2],[6]	114		46		6
Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows		$ 294		$ 206		$ 125	$ 90

[1] At March 31, 2024 and December 31, 2023, Dominion Energy had $41 million and $33 million, respectively, of cash and cash equivalents included in assets held for sale.

[2] Unless otherwise noted, restricted cash and equivalents balances are presented within other current assets in the Companies’ Consolidated Balance Sheets.

[3] See Note 15 for amounts attributable to VIEs.

[4] Dominion Energy’s Consolidated Balance Sheet at December 31, 2024 has been derived from the audited Consolidated Balance Sheet at that date.

[5] At both March 31, 2024 and December 31, 2023, Dominion Energy had $4 million of restricted cash and equivalents included in current assets held for sale with the remaining balances presented within other assets in Dominion Energy’s Consolidated Balance Sheets.

[6] Includes $108 million, $41 million and $6 million at VPFS attributable to VIEs at March 31, 2025, December 31, 2024 and March 31, 2024, respectively.

[7] See Note 15 for amounts attributable to VIEs.

[8] Virginia Power’s Consolidated Balance Sheet at December 31, 2024 has been derived from the audited Consolidated Balance Sheet at that date.