Income Taxes (Schedule of Deferred Income Taxes) (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Deferred income taxes:
Total deferred income tax assets	$ 1,854	$ 2,150
Total deferred income tax liabilities	8,266	8,771
Total net deferred income tax liabilities	6,412	6,621
Depreciation method and plant basis differences	4,878	4,588
Excess deferred income taxes	(790)	(811)
Unrecovered nuclear plant cost	420	450
DESC rate refund	(49)	(67)
Toshiba Settlement	(133)	(147)
Nuclear decommissioning	1,232	1,109
Deferred state income taxes	1,046	976
Federal benefit of deferred state income taxes	(230)	(220)
Deferred fuel, purchased energy and gas costs	189	299
Pension benefits	345	324
Other postretirement benefits	174	116
Loss and credit carryforwards	(680)	(1,022)
Deferred unamortized investment tax credits	(250)	(257)
Valuation allowances	113	130
Partnership basis differences	(30)	70
Total deferred taxes on stock held for sale	0	814
Other	177	269
Total net deferred income tax liabilities	6,412	6,621
Virginia Electric and Power Company
Deferred income taxes:
Total deferred income tax assets	1,082	1,281
Total deferred income tax liabilities	5,127	4,905
Total net deferred income tax liabilities	4,045	3,624
Depreciation method and plant basis differences	3,765	3,588
Excess deferred income taxes	(587)	(600)
Nuclear decommissioning	357	332
Deferred state income taxes	676	620
Federal benefit of deferred state income taxes	(142)	(130)
Deferred fuel, purchased energy and gas costs	178	267
Pension benefits	(116)	(110)
Other postretirement benefits	141	125
Loss and credit carryforwards	0	(309)
Deferred unamortized investment tax credits	(159)	(164)
Valuation allowances	0	8
Partnership basis differences	(98)	0
Other	30	(3)
Total net deferred income tax liabilities	$ 4,045	$ 3,624