Income Taxes (Schedule of Deferred Income Taxes) (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred income taxes:
Total deferred income tax assets	$ 2,150	$ 2,960
Total deferred income tax liabilities	8,761	7,981
Total net deferred income tax liabilities	6,611	5,021
Depreciation method and plant basis differences	4,588	4,449
Excess deferred income taxes	(811)	(847)
Unrecovered nuclear plant cost	450	479
DESC rate refund	(67)	(89)
Toshiba Settlement	(147)	(162)
Nuclear decommissioning	1,109	1,001
Deferred state income taxes	975	786
Federal benefit of deferred state income taxes	(220)	(160)
Deferred fuel, purchased energy and gas costs	299	509
Pension benefits	324	330
Other postretirement benefits	116	58
Loss and credit carryforwards	(1,022)	(1,782)
Deferred unamortized investment tax credits	(257)	(265)
Valuation allowances	130	137
Partnership basis differences	70	466
Total deferred taxes on stock held for sale	804	0
Other	270	111
Total net deferred income tax liabilities	6,611	5,021
Virginia Electric and Power Company
Deferred income taxes:
Total deferred income tax assets	1,281	1,695
Total deferred income tax liabilities	4,905	4,760
Total net deferred income tax liabilities	3,624	3,065
Depreciation method and plant basis differences	3,588	3,437
Excess deferred income taxes	(600)	(616)
Nuclear decommissioning	332	311
Deferred state income taxes	620	544
Federal benefit of deferred state income taxes	(130)	(114)
Deferred fuel, purchased energy and gas costs	267	403
Pension benefits	(110)	(105)
Other postretirement benefits	125	111
Loss and credit carryforwards	(309)	(751)
Deferred unamortized investment tax credits	(164)	(164)
Valuation allowances	8	7
Other	3	2
Total net deferred income tax liabilities	$ 3,624	$ 3,065