Financial Risk Management Activities (Schedule Of Derivative Instruments Not Designated As Hedging Instruments And Impact On Results Of Operations) (Detail) - Energy-Related Contracts [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (147)	$ 903
Operating Revenues [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(148)	902
Energy Costs [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 1	$ 1