Derivative Instruments (Notional Values) (Details) (Southern California Edison, Electric Utility, Economic hedges)	Sep. 30, 2013 GWh	Dec. 31, 2012 GWh
Electricity options, swaps and forwards (GWh)
Derivatives
Notional volumes of derivative instruments	8,964	15,884
Natural gas options, swaps and forwards (Bcf)
Derivatives
Notional volumes of derivative instruments	12	100
Congestion revenue rights (GWh)
Derivatives
Notional volumes of derivative instruments	127,772	149,774
Tolling arrangements (GWh)
Derivatives
Notional volumes of derivative instruments	97,893	101,485