Operating Segments (Narrative) (Details) - Operating Segments - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Dominion Energy South Carolina, Inc.
Segment Reporting Information [Line Items]
After- tax net expenses	$ 256	$ 7
SCANA
Segment Reporting Information [Line Items]
Litigation charges	70
Litigation charges, after tax	53
South Carolina Electric Base Rate Case
Segment Reporting Information [Line Items]
Settlement charges	266
Settlement charges net of tax	$ 199