Asset Retirement Obligations (Schedule of Reconciliation of the Carrying Amount of AROs) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021
Asset Retirement Obligation Disclosure [Abstract]
Beginning balance		$ 599	$ 597
Liabilities incurred		6	0
Liabilities settled		(1)	0
Accretion expense		26	25
Revisions in estimated cash flows	[1]	(2)	(23)
Ending balance		$ 628	$ 599

[1] The decrease in 2021 is due to the remeasurement of gas pipeline AROs.