Summary of Significant Accounting Policies (PPE) (Details) - SCE - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Depreciation	$ 2,000	$ 1,800	$ 1,700
Depreciation expense based on cost (as a percent)	3.70%	3.60%	3.60%
AFUDC equity capitalized during construction	$ 118	$ 121	$ 101
Potential impairment	186
Other income
Property, Plant and Equipment [Line Items]
AFUDC equity capitalized during construction	118	121	101
Interest expense
Property, Plant and Equipment [Line Items]
AFUDC debt capitalized during construction	50	$ 53	$ 63
2021 General Rate Case
Property, Plant and Equipment [Line Items]
Asset impairment	79
Asset impairment, net of tax	$ 47
Generation plant | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	10 years
Generation plant | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	55 years
Generation plant | Weighted Average
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	36 years
Distribution plant | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	20 years
Distribution plant | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	67 years
Distribution plant | Weighted Average
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	50 years
Transmission plant | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	45 years
Transmission plant | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	65 years
Transmission plant | Weighted Average
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	54 years
General plant and other | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
General plant and other | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	60 years
General plant and other | Weighted Average
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	26 years