Property, Plant and Equipment (Textual) (Details) - SCE - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Capitalized software costs	$ 1,200	$ 1,000
Capitalized software, accumulated amortization	600	400
Capitalized software, amortization expense	218	$ 190	$ 198
Capitalized software, estimated amortization year 1	213
Capitalized software, estimated amortization year 2	168
Capitalized software, estimated amortization year 3	136
Capitalized software, estimated amortization year 4	82
Capitalized software, estimated amortization year 5	$ 30
Capitalized software costs | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Capitalized software costs | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	7 years