Income Taxes (Income Tax Expense for Continuing Operations Including Noncontrolling Interests) (Detail) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
	Nov. 30, 2020	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current:
Federal			$ 7	$ (162)	$ (314)
State			46	45	(81)
Total current expense (benefit)			53	(117)	(395)
Deferred:
Taxes before operating loss carryforwards and investment tax credits			62	151	12
Tax utilization expense of operating loss carryforwards			36	43	44
Investment tax credits			(129)	250	311
State			32	(19)	72
Total deferred expense (benefit)			1	425	439
Investment tax credit-gross deferral			18	121	42
Investment tax credit-amortization			(4)	(4)	(3)
Total income tax expense	$ 336	$ 173	68	425	83
Virginia Electric and Power Company
Current:
Federal			17	67	364
State			(17)	(13)	71
Total current expense (benefit)			0	54	435
Deferred:
Taxes before operating loss carryforwards and investment tax credits			212	145	(226)
Tax utilization expense of operating loss carryforwards			0	0	0
Investment tax credits			(148)	(39)	(27)
State			112	118	7
Total deferred expense (benefit)			176	224	(246)
Investment tax credit-gross deferral			18	121	42
Investment tax credit-amortization			(3)	(2)	(2)
Total income tax expense			$ 191	$ 397	$ 229