Derivative Instruments (Notional Values) (Details) - Southern California Edison - Electric Utility - Economic Hedges	9 Months Ended	12 Months Ended
	Sep. 30, 2020 Bcfe GWh	Dec. 31, 2019 GWh Bcfe
Electricity options, swaps and forwards (GWh)
Derivative [Line Items]
Notional volumes of derivative instruments	2,338	3,155
Natural gas options, swaps and forwards (Bcf)
Derivative [Line Items]
Notional volumes of derivative instruments | Bcfe	30	43
Congestion revenue rights (GWh)
Derivative [Line Items]
Notional volumes of derivative instruments	43,229	48,170