Supplementary Financial Information (Schedule Of Intangible Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,701	$ 1,707
Accumulated Amortization	570	568
Net	1,131	1,139
Land Easements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	652	641
Accumulated Amortization	121	117
Net	531	524
Capitalized Software [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,049	1,066
Accumulated Amortization	449	451
Net	$ 600	$ 615