Income Taxes (Income Tax Expense for Continuing Operations Including Noncontrolling Interests) (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current:
Federal		$ (385)	$ (76)	$ (301)
State		(99)	27	13
Total current expense (benefit)		(484)	(49)	(288)
Deferred:
Taxes before operating loss carryforwards and investment tax credits		760	95	558
Tax utilization expense of operating loss carryforwards		45	35	42
State		282	73	(49)
Total deferred expense		1,087	203	551
Investment tax credits		(28)	(41)	(444)
Income tax expense (benefit)	$ 173	575	113	(181)
Virginia Electric and Power Company
Current:
Federal		(116)	17	67
State		6	(17)	(13)
Total current expense (benefit)		(110)	0	54
Deferred:
Taxes before operating loss carryforwards and investment tax credits		406	215	294
Tax utilization expense of operating loss carryforwards		0	0	0
State		107	108	116
Total deferred expense		513	323	410
Investment tax credits		(14)	(29)	(17)
Income tax expense (benefit)		$ 389	$ 294	$ 447