Financial Risk Management Activities (Schedule Of Reconciliation For Derivative Activity Included In Accumulated Other Comprehensive Loss) (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Less: Loss Reclassified into Income	$ (16)	$ (7)
Loss Recognized in AOCL	18	(65)
Less: Loss Reclassified into Income	(10)	(5)
Cash Flow Hedges [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Pre-Tax Balance at Beginning of Period	(4)	(9)	$ (9)
Loss Recognized in AOCL	(3)		0
Less: Loss Reclassified into Income	(1)		(5)
Pre-Tax Balance at End of Period	(6)		(4)
After-Tax Balance at Beginning of Period	(3)	(6)	(6)
Loss Recognized in AOCL	(2)	0	0
Less: Loss Reclassified into Income	(1)	$ (1)	(3)
After-Tax Balance at End of Period	$ (4)		$ (3)