Commitments and Contingencies (Southern California Wildfires and Mudslides) (Details) $ in Millions	1 Months Ended		3 Months Ended		12 Months Ended	28 Months Ended
	Apr. 30, 2020 USD ($)	Jul. 31, 2019 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Nov. 30, 2018 USD ($) a structure fatality	Mar. 31, 2020 USD ($)	Jan. 31, 2019 claim	Jan. 31, 2018 structure fatality	Dec. 04, 2017 a structure fatality
Loss Contingencies [Line Items]
Estimated losses			$ 4,568	$ 4,568		$ 4,568
San Onofre OII
Loss Contingencies [Line Items]
Derivative lawsuits | claim							2
2017/2018 Wildfire/Mudslide Event
Loss Contingencies [Line Items]
Estimated losses			4,500	4,500		4,500
Expected insurance recoveries			$ 1,700			1,700
Southern California Edison
Loss Contingencies [Line Items]
High fire risk service area, percent			27.00%
Estimated losses			$ 4,568	4,568		4,568
Wildfire-specific insurance coverage					$ 1,000
Self-insured retention			10
Southern California Edison | CPUC
Loss Contingencies [Line Items]
Requested rate increase		$ 478
Southern California Edison | Thomas and Koenigstein Fires
Loss Contingencies [Line Items]
Acres burned | a									280,000
Structures destroyed | structure									1,343
Fatalities | fatality									2
Southern California Edison | Thomas and Koenigstein Fires | CPUC
Loss Contingencies [Line Items]
Requested rate increase		$ 6
Southern California Edison | Woolsey Fire
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-specific insurance coverage			1,000
Self-insured retention			10
Southern California Edison | Montecito Mudslides
Loss Contingencies [Line Items]
Structures destroyed | structure								135
Fatalities | fatality								21
Structures damaged | structure								324
Additional presumed fatalities | fatality								2
Southern California Edison | 2017/2018 Wildfire/Mudslide Event
Loss Contingencies [Line Items]
Estimated losses			4,500	4,500		4,500
Expected insurance recoveries			1,652	1,710		1,652
Expected revenue from FERC customers			113	149		113
Payments			360	$ 360
Accrued losses			4,900
Insurance recoveries			$ 58			$ 348
Southern California Edison | 2017/2018 Wildfire/Mudslide Event | Subsequent event
Loss Contingencies [Line Items]
Insurance recoveries	$ 15