Derivative Instruments (Notional Values) (Details) (Southern California Edison, Electric Utility, Gross amounts recognized)	Dec. 31, 2014 MWh	Dec. 31, 2013 MWh
Electricity options, swaps and forwards (GWh)
Derivatives
Notional volumes of derivative instruments	4,000	6,000
Natural gas options, swaps and forwards (Bcf)
Derivatives
Notional volumes of derivative instruments	0	0
Congestion revenue rights (GWh)
Derivatives
Notional volumes of derivative instruments	123,000	149,000
Tolling arrangements (GWh)
Derivatives
Notional volumes of derivative instruments	80,000	88,000