Derivative Instruments (Notional Values) (Details) - Southern California Edison - Electric Utility - Economic hedges GWh in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016 Bcfe GWh	Dec. 31, 2015 Bcfe GWh
Electricity options, swaps and forwards (GWh)
Derivatives
Notional volumes of derivative instruments	4,842	6,221
Natural gas options, swaps and forwards (Bcf)
Derivatives
Notional volumes of derivative instruments | Bcfe	17	32
Congestion revenue rights (GWh)
Derivatives
Notional volumes of derivative instruments	96,182	109,740
Tolling arrangements (GWh)
Derivatives
Notional volumes of derivative instruments	68,331	70,663