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
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				$ 45		$ 43
SCE
Loss Contingencies [Line Items]
Damages sought			$ 112
Litigation settlement		124
Legal and other costs		$ 2
Damage award, customer	$ 106
Damage awarded, shareholders	17
Claim to recover damages incurred				35	$ 58	$ 34
Disallowed claim amount				$ 13
SCE | Regulatory balancing and memorandum accounts
Loss Contingencies [Line Items]
Damage award, customer	$ 72