Commitments and Contingencies (Spent Nuclear Fuel) (Details) - USD ($) $ in Millions	1 Months Ended
	Apr. 30, 2016	Jun. 30, 2010	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			$ 34	$ 56