Operating Segments - Schedule of Segment Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
External revenue	[1]	$ 3,028	$ 3,783	$ 3,146
Depreciation and amortization		531	507	486
Interest charges, net of AFUDC	[1]	250	220	192
Income tax expense (benefit)		85	131	9
Comprehensive income (loss) available (attributable) to common shareholder		375	482	209
Capital expenditures		957	697	758
Total assets		15,857	15,749
Dominion Energy South Carolina, Inc. [Member]
Segment Reporting Information [Line Items]
External revenue		3,028	3,783	3,146
Depreciation and amortization		531	507	486
Interest charges, net of AFUDC		250	220	215
Income tax expense (benefit)		79	132	125
Comprehensive income (loss) available (attributable) to common shareholder		357	485	421
Capital expenditures		957	697	758
Total assets		15,900	15,700
Corporate and Other
Segment Reporting Information [Line Items]
External revenue		0	0	0
Depreciation and amortization		0	0	0
Interest charges, net of AFUDC		0	0	(23)
Income tax expense (benefit)		6	(1)	(116)
Comprehensive income (loss) available (attributable) to common shareholder		18	(3)	(212)
Capital expenditures		0	0	$ 0
Total assets		$ 0	$ 0

[1] See Note 16 for amounts attributable to affiliates.