Commitments and Contingencies (Contingencies) (Details)	1 Months Ended	3 Months Ended		12 Months Ended			24 Months Ended
	Jul. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Nov. 30, 2018 USD ($) a structure fatality	Dec. 31, 2019 USD ($)	Jan. 31, 2019 claim	Jan. 01, 2018 structure fatality	Dec. 04, 2017 a structure fatality
Loss Contingencies [Line Items]
Charge for wildfire-related claims		$ 4,568,000,000	$ 4,669,000,000	$ 4,568,000,000	$ 4,669,000,000		$ 4,568,000,000
San Onofre OII
Loss Contingencies [Line Items]
Lawsuits | claim								2
2017/2018 Wildfire/Mudslide Events
Loss Contingencies [Line Items]
Charge for wildfire-related claims		4,541,000,000	4,669,000,000	4,541,000,000	4,669,000,000		4,541,000,000
Accrued losses				232,000,000
Payments				$ 360,000,000
SCE
Loss Contingencies [Line Items]
High fire risk service area, percent				27.00%
Charge for wildfire-related claims		4,568,000,000	4,669,000,000	$ 4,568,000,000	4,669,000,000		4,568,000,000
Wildfire insurance coverage					1,000,000,000.0	$ 300,000,000
Self insurance					10,000,000
SCE | California Public Utilities Commission
Loss Contingencies [Line Items]
Requested rate amount	$ 478,000,000
SCE | December 2017 Wildfires
Loss Contingencies [Line Items]
Acres burned | a										280,000
Structures destroyed | structure										1,343
Fatalities | fatality										2
SCE | December 2017 Wildfires | California Public Utilities Commission
Loss Contingencies [Line Items]
Requested rate amount	$ 6,000,000
SCE | November 2018 Wildfires
Loss Contingencies [Line Items]
Acres burned | a						100,000
Structures destroyed | structure						1,643
Fatalities | fatality						3
Structures damaged | structure						364
Additional fatalities | fatality						2
Wildfire insurance coverage					1,000,000,000.0
Self insurance					10,000,000
SCE | Montecito Mudslides
Loss Contingencies [Line Items]
Fatalities | fatality									21
Structures damaged						135			324
Additional fatalities presumed | fatality									2
SCE | Saddle Ridge Fire
Loss Contingencies [Line Items]
Self-insured retention expenses				23,000,000
Self-insured retention expenses after tax				17,000,000
SCE | 2017/2018 Wildfire/Mudslide Events
Loss Contingencies [Line Items]
Charge for wildfire-related claims		4,500,000,000	4,700,000,000	4,500,000,000	4,700,000,000		4,500,000,000
Expected insurance recoveries		1,710,000,000	2,000,000,000	1,710,000,000	2,000,000,000		1,710,000,000
Expected revenue from FERC customers		149,000,000		149,000,000			149,000,000
Accrued losses		232,000,000	$ 2,500,000,000	232,000,000	$ 4,669,000,000		$ 4,900,000,000
Payments		$ 360,000,000		360,000,000
Settlements and recoveries				$ 290,000,000