Commitments and Contingencies (Spent Nuclear Fuel) (Details) - USD ($) $ in Millions	1 Months Ended
	Aug. 31, 2018	Apr. 30, 2016	Jun. 30, 2010	May 31, 2018	Oct. 31, 2017	Feb. 28, 2017	Sep. 30, 2016
Schedule Of Commitments And Contingencies [Line Items]
DOE determination of claim reimbursement							$ 56.0
SCE and other owners of San Onofre and Palo Verde
Schedule Of Commitments And Contingencies [Line Items]
Damages sought			$ 142.0
Damage award		$ 162.0
DOE determination of claim reimbursement				$ 45.0		$ 43.0
Southern California Edison
Schedule Of Commitments And Contingencies [Line Items]
Damages sought			$ 112.0
Damage award		124.0
Legal and other costs		$ 2.0
Damage award, customers	$ 105.6
Damage award, shareholders	16.6
DOE determination of claim reimbursement				35.0	$ 58.0	$ 34.0
Disallowed claim amount				$ 13.0
Southern California Edison | Regulatory balancing accounts
Schedule Of Commitments And Contingencies [Line Items]
Damage award, customers	$ 71.6