Acquisitions and Dispositions (Schedule of Unaudited Pro Forma Information) (Detail) - SCANA - USD ($) $ / shares in Units, $ in Millions		3 Months Ended	9 Months Ended
		Sep. 30, 2019	Sep. 30, 2019
Business Acquisition [Line Items]
Operating Revenue	[1]	$ 3,782	$ 11,513
Net income attributable to Dominion Energy	[1]	$ 1,029	$ 1,991
Earnings Per Common Share – Basic	[1]	$ 1.28	$ 2.47
Earnings Per Common Share – Diluted	[1]	$ 1.26	$ 2.44

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