Compensation and Benefit Plans (Textual) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($)
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 18
Estimated future contributions in remainder of year	48
PBOP Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	3
Estimated future contributions in remainder of year	9
Southern California Edison | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	13
Estimated future contributions in remainder of year	$ 37