Acquisitions and Dispositions (Schedule of Unaudited Pro Forma Information) (Detail) - SCANA - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Operating Revenue	[1]	$ 17,579	$ 17,505
Net income attributable to Dominion Energy	[1]	$ 3,266	$ 2,081
Earnings Per Common Share - Basic	[1]	$ 4.04	$ 2.78
Earnings Per Common Share - Diluted	[1]	$ 4.00	$ 2.77

[1] Amounts include adjustments for non-recurring costs directly related to the SCANA Combination.