Regulatory Assets and Liabilities (Textual) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 19, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Regulatory assets	$ 4,914		$ 7,455
SCE
Regulatory Assets [Line Items]
Regulatory assets	$ 4,914		$ 7,455
Regulatory assets, energy derivatives, low range of contract expiration (in years)	3 years
Regulatory assets, energy derivatives, high range of contract expiration (in years)	6 years
Regulatory assets related to deferred income taxes, recovery period, low range (in years)	1 year
Regulatory assets related to deferred income taxes, recovery period, high range (in years)	60 years
Low end of the range of remaining original amortization (in years)	10 years
High end of the range of remaining original amortization (in years)	35 years
Unamortized investments, net of accumulated amortization | SCE
Regulatory Assets [Line Items]
Return rate earned on assets included in rate base (as a percent)	7.90%		7.90%
Regulatory assets	$ 123		$ 80
Unamortized investments, net of accumulated amortization | SCE | Legacy Meters
Regulatory Assets [Line Items]
Return rate earned on assets included in rate base (as a percent)	6.46%		6.46%
San Onofre | SCE
Regulatory Assets [Line Items]
Regulatory assets	$ 72	$ 775	$ 857