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, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Net income (loss) from continuing operations		$ (452)	$ 259	$ 240	$ 1,239
Preferred stock dividends (see Note 16)		(25)	(16)	(52)	(32)
Net income (loss) attributable to Dominion Energy from continuing operations – Basic		(477)	243	188	1,207
Net income (loss) attributable to Dominion Energy from continuing operations - Diluted		(477)	243	188	1,207
Net income (loss) from discontinued operations		$ (1)	$ 26	$ 18	$ 54
Average shares of common stock outstanding – Basic		818.4	806.6	814.5	806.2
Net effect of dilutive securities	[1],[2]			1.4	0.1
Average shares of common stock outstanding – Diluted		818.4	806.6	815.9	806.3
EPS from continuing operations – Basic		$ (0.58)	$ 0.30	$ 0.23	$ 1.49
EPS from discontinued operations – Basic			0.03	0.02	0.07
Net income (loss) attributable to Dominion Energy		(0.58)	0.33	0.25	1.56
EPS from continuing operations – Diluted		(0.58)	0.30	0.23	1.49
EPS from discontinued operations – Diluted			0.03	0.02	0.07
Net income (loss) attributable to Dominion Energy		$ (0.58)	$ 0.33	$ 0.25	$ 1.56

[1] As a result of a net loss from continuing operations 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] Dilutive securities for the six months ended June 30, 2022 consist primarily of stock expected to be issued to satisfy the obligation under a settlement agreement with the SCDOR (applying the if converted method) as well as forward sales agreements entered into in November 2021 (applying the treasury stock method). See Notes 16 and 17 for additional information.