Operating Segments - Schedule of Segment Information (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
External revenue	[1]	$ 775	$ 759
Comprehensive income (loss) available (attributable) to common shareholder		74	92
Dominion Energy South Carolina, Inc. [Member]
Segment Reporting Information [Line Items]
External revenue		775	759
Comprehensive income (loss) available (attributable) to common shareholder		75	86
Corporate and Other
Segment Reporting Information [Line Items]
External revenue		0	0
Comprehensive income (loss) available (attributable) to common shareholder		$ (1)	$ 6

[1] See Note 12 for amounts attributable to affiliates.