Income Taxes (Schedule of Deferred Income Taxes) (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Deferred income taxes:
Total deferred income tax assets	$ 2,869	$ 3,025
Total deferred income tax liabilities	9,267	9,397
Total net deferred income tax liabilities	6,398	6,372
Plant and equipment, primarily depreciation method and basis differences	5,545	6,017
Excess deferred income taxes	(1,060)	(1,107)
Unrecovered NND Project costs	479	508
DESC rate refund	(89)	(113)
Toshiba Settlement	(162)	(189)
Nuclear decommissioning	1,001	1,114
Deferred state income taxes	892	857
Federal benefit of deferred state income taxes	(199)	(179)
Deferred fuel, purchased energy and gas costs	579	189
Pension benefits	414	362
Other postretirement benefits	73	73
Loss and credit carryforwards	(1,790)	(1,571)
Valuation allowances	138	140
Partnership basis differences	470	398
Other	107	(127)
Total net deferred income tax liabilities	6,398	6,372
Deferred Investment Tax Credits – Regulated Operations	300	286
Total Deferred Taxes and Deferred Investment Tax Credits	6,698	6,658
Virginia Electric and Power Company
Deferred income taxes:
Total deferred income tax assets	1,535	1,373
Total deferred income tax liabilities	4,701	4,286
Total net deferred income tax liabilities	3,166	2,913
Plant and equipment, primarily depreciation method and basis differences	3,355	3,327
Excess deferred income taxes	(616)	(629)
Nuclear decommissioning	311	324
Deferred state income taxes	566	420
Federal benefit of deferred state income taxes	(119)	(88)
Deferred fuel, purchased energy and gas costs	403	126
Pension benefits	(105)	(119)
Other postretirement benefits	111	93
Loss and credit carryforwards	(751)	(537)
Valuation allowances	7	6
Other	4	(10)
Total net deferred income tax liabilities	3,166	2,913
Deferred Investment Tax Credits – Regulated Operations	286	270
Total Deferred Taxes and Deferred Investment Tax Credits	$ 3,452	$ 3,183