Commitments and Contingencies (Spent Nuclear Fuel) (Details) - USD ($) $ in Millions	1 Months Ended
	Apr. 30, 2016	Jun. 30, 2010	Oct. 30, 2017	Feb. 28, 2017	Sep. 30, 2016
Loss Contingencies [Line Items]
Claim to recover damages incurred					$ 56
SCE and other owners of San Onofre and Palo Verde
Loss Contingencies [Line Items]
Damages sought		$ 142
Litigation settlement	$ 162
Claim to recover damages incurred				$ 43
SCE
Loss Contingencies [Line Items]
Damages sought		$ 112
Litigation settlement	$ 124
Claim to recover damages incurred			$ 59	$ 34