Derivative Instruments (Notional Values) (Details) - SCE	6 Months Ended	12 Months Ended
	Jun. 30, 2021 Bcfe GWh	Dec. 31, 2020 Bcfe GWh
Electricity options, swaps and forwards (GWh)
Derivatives
Notional volumes of derivative instruments	647	1,581
Natural gas options, swaps and forwards (Bcf)
Derivatives
Notional volumes of derivative instruments | Bcfe	53	34
Congestion revenue rights (GWh)
Derivatives
Notional volumes of derivative instruments	29,285	41,151