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, 2022	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Gain (Loss) Recognized in AOCI, After-Tax	$ (230)	$ 143	$ (11)
Less: Loss Reclassified to Income, After-Tax	30	11	(4)
Pre-Tax Amount	(49)	(15)	12
Cash Flow Hedges
Derivative [Line Items]
Balance as of Beginning of Year	(9)	(13)
Balance as of End of Year	(4)	(9)	(13)
Balance as of Beginning of Year	(6)	(9)
Gain (Loss) Recognized in AOCI, After-Tax	0	0	(4)
Less: Loss Reclassified to Income, After-Tax	3	3	10
Balance as of End of Year	(3)	(6)	(9)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0	0
Pre-Tax Amount	$ (5)	$ (4)	$ (14)