Financial Risk Management Activities (Schedule Of Gross Volume, On Absolute Basis For Derivative Contracts) (Detail) $ / mwh in Millions, $ / Derivative in Millions, $ / DTH in Millions	12 Months Ended
	Dec. 31, 2023 $ / mwh $ / DTH $ / Derivative	Dec. 31, 2022 $ / mwh $ / DTH $ / Derivative
Natural Gas Dth [Member]
Derivative [Line Items]
Gross volume of derivative on absolute value basis | $ / DTH	66	49
Electricity MWh [Member]
Derivative [Line Items]
Gross volume of derivative on absolute value basis | $ / mwh	(60)	(60)
FTRs MWh [Member]
Derivative [Line Items]
Gross volume of derivative on absolute value basis | $ / mwh	19	24
Interest Rate Swaps [Member]
Derivative [Line Items]
Gross volume of derivative on absolute value basis | $ / Derivative	1,400
Interest Rate Contract
Derivative [Line Items]
Gross volume of derivative on absolute value basis | $ / Derivative	2,000	1,050