Other Income, Net (Components of Other Income, Net) (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Other income		$ 2	$ 3	$ 5	$ 10
Other expense		(1)	1	0	(15)
Gains on sales of assets	[1]	20	0	37	0
Allowance for equity funds used during construction		1	2	4	5
Other income, net		$ 22	$ 6	$ 46	$ 0

[1] Includes amounts recognized in connection with the transfer of property to satisfy litigation.  See Note 10 for additional information.