Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ (10,681)	$ (9,958)
Total utility property, plant and equipment	47,653	44,198
SCE
Property, Plant and Equipment [Line Items]
Distribution	28,663	26,929
Transmission	15,669	14,720
Generation	3,709	3,664
General plant and other	5,129	4,583
Accumulated depreciation	(10,681)	(9,958)
Total utility property, plant and equipment, Gross	42,489	39,938
Construction work in progress	5,033	4,131
Nuclear fuel, at amortized cost	131	129
Total utility property, plant and equipment	$ 47,653	$ 44,198