Financial Risk Management Activities (Schedule Of Derivative Instruments Designated As Cash Flow Hedges) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-Tax Gain (Loss) attributed to Cash Flow Hedges Recognized in AOCI on Derivatives (Effective Portion)	$ 13	$ 0	$ 0
Amount of Pre-Tax Loss Reclassified from AOCL into Income, Effective Portion	5	(5)	(4)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	225	30	11
Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-Tax Gain (Loss) attributed to Cash Flow Hedges Recognized in AOCI on Derivatives (Effective Portion)	13	0	0
Amount of Pre-Tax Loss Reclassified from AOCL into Income, Effective Portion	5	(5)	(4)
Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(3)	3	3
Cash Flow Hedges | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	$ (3)	$ 3	$ 3