Earnings Per Share (Calculation of Basic and Diluted EPS) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share [Abstract]
Net income attributable to Dominion Energy from continuing operations		$ 967	$ 698	$ 2,018	$ 1,813
Preferred stock dividends (see Note 16)		(15)	(20)	(54)	(60)
Preferred stock deemed dividends (see Note 16)		0	0	(9)	0
Net income attributable to Dominion Energy from continuing operations - Basic		952	678	1,955	1,753
Net income attributable to Dominion Energy from continuing operations - Diluted		952	678	1,955	1,753
Net income (loss) attributable to Dominion Energy		$ (13)	$ (541)	$ 182	$ (92)
Average shares of common stock outstanding – Basic		839.0	836.8	838.3	836.0
Net effect of dilutive securities	[1]	0.3	0.0	0.1	0.2
Average shares of common stock outstanding – Diluted		839.3	836.8	838.4	836.2
EPS from continuing operations – Basic		$ 1.14	$ 0.81	$ 2.33	$ 2.10
EPS from discontinued operations – Basic		(0.02)	(0.65)	0.22	(0.11)
Net income attributable to Dominion Energy		1.12	0.16	2.55	1.99
EPS from continuing operations – Diluted		1.14	0.81	2.33	2.10
EPS from discontinued operations – Diluted		(0.02)	(0.65)	0.22	(0.11)
Net income attributable to Dominion Energy		$ 1.12	$ 0.16	$ 2.55	$ 1.99

[1] Dilutive securities for the three and nine months ended September 30, 2024 consists of certain of the forward sales agreements entered into in the second and third quarters of 2024 (applying the treasury stock method). Dilutive securities for the nine months ended September 30, 2023 include stock potentially to be issued to satisfy the obligation under a settlement agreement with the SCDOR (applying the if converted method). See Notes 16 and 17 for additional information.