Derivative Instruments (Notional Values) (Details) (Southern California Edison, Electric Utility, Economic hedges)	Jun. 30, 2013 GWh	Dec. 31, 2012 GWh
Electricity options, swaps and forwards (GWh)
Derivatives
Notional volumes of derivative instruments	11,460	15,884
Natural gas options, swaps and forwards (Bcf)
Derivatives
Notional volumes of derivative instruments	38	100
Congestion revenue rights (GWh)
Derivatives
Notional volumes of derivative instruments	124,973	149,774
Tolling arrangements (GWh)
Derivatives
Notional volumes of derivative instruments	99,926	101,485