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, 2022	Mar. 31, 2021	Dec. 31, 2021
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Less: Loss Reclassified into Income	$ (7)	$ (3)
Loss Recognized in AOCL	(65)	(40)
Less: Loss Reclassified into Income	(5)	(2)
Cash Flow Hedges [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Pre-Tax Balance at Beginning of Period	(9)	(13)	$ (13)
Loss Recognized in AOCL	0		0
Less: Loss Reclassified into Income	(1)		(4)
Pre-Tax Balance at End of Period	(8)		(9)
After-Tax Balance at Beginning of Period	(6)	(9)	(9)
Loss Recognized in AOCL	0	0	0
Less: Loss Reclassified into Income	(1)	$ (1)	(3)
After-Tax Balance at End of Period	$ (5)		$ (6)