Commitments and Contingencies (Southern California Wildfires and Mudslides) (Details) a in Thousands	1 Months Ended				3 Months Ended			6 Months Ended	9 Months Ended		12 Months Ended	13 Months Ended	31 Months Ended
	Oct. 27, 2020 USD ($)	Oct. 19, 2020 USD ($) a structure injury	Oct. 31, 2019 a fatality structure injury	Jul. 31, 2019 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Nov. 30, 2018 USD ($) a structure fatality	Jun. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Jan. 31, 2019 claim	Jan. 31, 2018 structure fatality	Dec. 04, 2017 a fatality structure
San Onofre OII
Loss Contingencies [Line Items]
Derivative lawsuits | claim														2
2017/2018 Wildfire/Mudslide Event
Loss Contingencies [Line Items]
Estimated losses					$ 4,600,000,000	$ 4,541,000,000	$ 5,801,000,000	$ 4,600,000,000	$ 4,600,000,000	$ 5,801,000,000		$ 4,500,000,000	$ 4,500,000,000
Charge for wildfire-related claims					1,297,000,000		0		1,297,000,000	0
Expected revenue from FERC customers					84,000,000		0		84,000,000	0
Net charge to earnings					1,213,000,000		0		1,213,000,000	0
Total after-tax charge					874,000,000		0		874,000,000	0
Total estimated liabilities					5,800,000,000			5,800,000,000	5,800,000,000
Fixed payments to be made under executed settlement agreements3					1,192,000,000			1,192,000,000	1,192,000,000
Loss estimate balance					4,609,000,000			4,609,000,000	4,609,000,000
Remaining expected insurance recoveries					1,600,000,000			1,600,000,000	1,600,000,000
Expected insurance recoveries					0		0		0	0
Cumulative expected recoveries									125,000,000
Amounts paid									37,000,000
Payments and settlements									$ 1,192,000,000
Southern California Edison
Loss Contingencies [Line Items]
High fire risk service area, percent									27.00%
Wildfire-specific insurance coverage											$ 1,000,000,000.0	1,200,000,000
Self-insured retention									$ 10,000,000			50,000,000
Southern California Edison | CPUC
Loss Contingencies [Line Items]
Requested rate increase				$ 478,000,000
Southern California Edison | Thomas and Koenigstein Fires
Loss Contingencies [Line Items]
Acres burned | a																280
Structures destroyed | structure																1,343
Fatalities | fatality																2
Southern California Edison | Thomas and Koenigstein Fires | CPUC
Loss Contingencies [Line Items]
Requested rate increase				$ 6,000,000
Southern California Edison | Woolsey Fire
Loss Contingencies [Line Items]
Acres burned | a											100
Structures destroyed | structure											1,643
Fatalities | fatality											3
Structures damaged | structure											364
Additional fatalities | fatality											2
Wildfire-specific insurance coverage									1,000,000,000.0
Self-insured retention									10,000,000
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 | Saddle Ridge
Loss Contingencies [Line Items]
Acres burned | a			9
Structures destroyed | structure			19
Fatalities | fatality			1
Structures damaged | structure			88
Number of injured firefighters | injury			8
Southern California Edison | Bobcat fire | Subsequent event
Loss Contingencies [Line Items]
Acres burned | a		116
Number of injured firefighters | injury		6
Estimated fire suppression costs		$ 80,000,000
Southern California Edison | Bobcat fire | Subsequent event | Homes
Loss Contingencies [Line Items]
Structures destroyed | structure		87
Structures damaged | structure		28
Southern California Edison | Bobcat fire | Subsequent event | Commercial property
Loss Contingencies [Line Items]
Structures destroyed | structure		1
Southern California Edison | Bobcat fire | Subsequent event | Minor structures
Loss Contingencies [Line Items]
Structures destroyed | structure		83
Structures damaged | structure		19
Southern California Edison | 2017/2018 Wildfire/Mudslide Event
Loss Contingencies [Line Items]
Estimated losses					4,600,000,000	4,541,000,000	5,801,000,000	4,600,000,000	4,600,000,000	5,801,000,000		$ 4,500,000,000	4,500,000,000
Charge for wildfire-related claims					1,297,000,000		0		1,297,000,000	0			6,200,000,000
Expected revenue from FERC customers					84,000,000		0		84,000,000	0
Net charge to earnings					1,213,000,000		0		1,213,000,000	0
Total after-tax charge					874,000,000		0		874,000,000	0
Total estimated liabilities					5,800,000,000			5,800,000,000	5,800,000,000
Fixed payments to be made under executed settlement agreements3					1,192,000,000			1,192,000,000	1,192,000,000
Loss estimate balance					4,609,000,000			4,609,000,000	4,609,000,000
Remaining expected insurance recoveries					1,637,000,000	1,710,000,000		1,637,000,000	1,637,000,000
Expected insurance recoveries					0		$ 0		0	$ 0
Cumulative expected recoveries									125,000,000
Amounts paid						360,000,000			37,000,000
Payment agreement for each dollar of claim					0.555
Litigation settlement								73,000,000
Payments and settlements									1,192,000,000				1,600,000,000
Insurance recoveries									73,000,000				$ 363,000,000
Estimated recoveries						$ 233,000,000
Southern California Edison | 2017/2018 Wildfire/Mudslide Event | Short-term asset
Loss Contingencies [Line Items]
Remaining expected insurance recoveries					843,000,000			843,000,000	843,000,000
Southern California Edison | 2017/2018 Wildfire/Mudslide Event | Other long-term assets
Loss Contingencies [Line Items]
Remaining expected insurance recoveries					$ 794,000,000			$ 794,000,000	$ 794,000,000
Southern California Edison | 2017/2018 Wildfire/Mudslide Event | Subsequent event
Loss Contingencies [Line Items]
Amounts paid	$ 1,200,000,000