Supplementary Financial Information (Schedule Of Property, Plant And Equipment) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Property Plant and Equipment [Line Items]
Total assets in service	$ 31,299	$ 31,029
Less accumulated depreciation	8,771	8,659
Net of accumulated depreciation	22,528	22,370
Construction work in progress	835	557
Held for future use	27	27
Property, plant and equipment - net	23,390	22,954
Distribution [Member]
Property Plant and Equipment [Line Items]
Total assets in service	$ 16,244	15,994
Composite depreciation rate	2.50%
Avg. life	39 years 6 months
Transmission [Member]
Property Plant and Equipment [Line Items]
Total assets in service	$ 13,083	13,075
Composite depreciation rate	2.90%
Avg. life	34 years 7 months 6 days
Other Assets [Member]
Property Plant and Equipment [Line Items]
Total assets in service	$ 1,972	$ 1,960
Composite depreciation rate	5.80%
Avg. life	17 years 3 months 18 days