Earnings Per Share (Calculation of Basic and Diluted EPS) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Net income (loss) from continuing operations		$ 586	$ (452)	$ 1,588	$ 240
Preferred stock dividends (see Note 16)		(20)	(25)	(40)	(52)
Net income (loss) attributable to Dominion Energy from continuing operations - Basic		566	(477)	1,548	188
Dilutive effect of Series A Preferred Stock	[1],[2]	0	0	0	0
Net income (loss) attributable to Dominion Energy from continuing operations - Diluted		566	(477)	1,548	188
Net income attributable to Dominion Energy		$ 13	$ (1)	$ 8	$ 18
Average shares of common stock outstanding – Basic		836.0	818.4	835.6	814.5
Net effect of dilutive securities	[1],[3]	0.2	0.0	0.3	1.4
Average shares of common stock outstanding – Diluted		836.2	818.4	835.9	815.9
EPS from continuing operations – Basic		$ 0.67	$ (0.58)	$ 1.85	$ 0.23
EPS from discontinued operations – Basic		0.02	0	0.01	0.02
Net income (loss) attributable to Dominion Energy		0.69	(0.58)	1.86	0.25
EPS from continuing operations – Diluted		0.67	(0.58)	1.85	0.23
EPS from discontinued operations – Diluted		0.02	0	0.01	0.02
Net income (loss) attributable to Dominion Energy		$ 0.69	$ (0.58)	$ 1.86	$ 0.25

[1] As a result of a net loss for the three months ended June 30, 2022, any adjustments to earnings or shares would be considered antidilutive and are therefore excluded from the calculation of diluted EPS.

[2] Effective January 2022, diluted net income was no longer reduced by the Series A Preferred Stock dividends.

[3] Dilutive securities for the three and six months ended June 30, 2023 and the six months ended June 30, 2022 include stock potentially to be issued to satisfy the obligation under a settlement agreement with the SCDOR (applying the if converted method). See Note 17 for additional information. Additionally, dilutive securities for the six months ended June 30, 2022 included forward sales agreements entered into in November 2021 (applying the treasury stock method). See Note 20 to the Consolidated Financial Statements in Dominion Energy’s Annual Report on Form 10-K for the year ended December 31, 2022 for additional information.