Supplementary Financial Information (Schedule Of Property, Plant And Equipment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property Plant and Equipment [Line Items]
Total assets in service	$ 31,029	$ 28,948
Less accumulated depreciation	8,659	8,336
Net of accumulated depreciation	22,370	20,612
Construction work in progress	557	593
Held for future use	27	20
Property, plant and equipment - net	22,954	21,225
Distribution [Member]
Property Plant and Equipment [Line Items]
Total assets in service	$ 15,994	14,937
Composite depreciation rate	2.50%
Avg. life	39 years 6 months
Transmission [Member]
Property Plant and Equipment [Line Items]
Total assets in service	$ 13,075	12,156
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	$ 1,960	$ 1,855
Composite depreciation rate	5.50%
Avg. life	18 years 2 months 12 days