Earnings Per Share (Calculation of Basic and Diluted EPS) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Net income from continuing operations		$ 692	$ 980
Preferred stock dividends (see Note 16)		(27)	(16)
Net income attributable to Dominion Energy from continuing operations – Basic		665	964
Dilutive effect of 2019 Equity Units	[1]	7
Net income attributable to Dominion Energy from continuing operations - Diluted		672	964
Net income from discontinued operations		$ 19	$ 28
Average shares of common stock outstanding – Basic		810.6	805.9
Net effect of dilutive securities	[2]	21.4
Average shares of common stock outstanding – Diluted		832.0	805.9
EPS from continuing operations – Basic		$ 0.82	$ 1.19
EPS from discontinued operations – Basic		0.02	0.04
EPS attributable to Dominion Energy – Basic		0.84	1.23
EPS from continuing operations – Diluted		0.81	1.19
EPS from discontinued operations – Diluted		0.02	0.04
EPS attributable to Dominion Energy – Diluted		$ 0.83	$ 1.23

[1] In accordance with revised accounting standards effective January 2022, a fair value adjustment, if dilutive, of the Series A Preferred Stock is no longer included in applying the if converted method to the 2019 Equity Units. In addition, diluted net income is no longer reduced by the Series A Preferred Stock dividends. No fair value adjustment was necessary for the three months ended March 31, 2021.

[2] Dilutive securities for 2022 consist primarily of the 2019 Equity Units (applying the if converted method as updated effective January 2022), 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.