Financial Risk Management Activities (Schedule Of Reconciliation For Derivative Activity Included In Accumulated Other Comprehensive Loss) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative [Line Items]
Gain (Loss) Recognized in AOCI, After-Tax	$ 146	$ (230)	$ 143
Less: Loss Reclassified to Income, After-Tax	225	30	11
Pre-Tax Amount	(307)	(49)	(15)
Cash Flow Hedges
Derivative [Line Items]
Balance as of Beginning of Year	(4)	(9)
Balance as of End of Year	4	(4)	(9)
Balance as of Beginning of Year	(3)	(6)
Gain (Loss) Recognized in AOCI, After-Tax	9	0	0
Less: Loss Reclassified to Income, After-Tax	(3)	3	3
Balance as of End of Year	3	(3)	(6)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	13	0
Pre-Tax Amount	$ 5	$ (5)	$ (4)