Commitments and Contingencies (Spent Nuclear Fuel) (Details) - USD ($) $ in Millions	1 Months Ended
	Aug. 30, 2017	Apr. 30, 2016	Jun. 30, 2010	Oct. 30, 2017	Feb. 28, 2017	Sep. 30, 2016
SCE and other owners of San Onofre and Palo Verde
Schedule Of Commitments And Contingencies [Line Items]
Damages sought			$ 142
Damage award		$ 162
Claim to recover damages incurred					$ 43
Southern California Edison
Schedule Of Commitments And Contingencies [Line Items]
Damages sought			$ 112
Damage award		$ 124
Claim to recover damages incurred				$ 59	$ 34	$ 56
Alternative site exploration	$ 4