Summary of Significant Accounting Policies (Wildfire Insurance Fund and AB 1054) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Regulatory Assets [Line Items]
Wildfire Insurance Fund contributions long term	$ 2,849	$ 2,849	$ 2,849		$ 0
Wildfire Insurance Fund contributions current	323	323	323		0
Contributions to Wildfire Insurance Fund			2,363	$ 0
Insurance fund liability included in other long-term liabilities	782	782	782
Insurance fund liability included in accounts payable	94	$ 94	94
Amortization period		10 years
Historical term
Regulatory Assets [Line Items]
Historical term used in estimate		5 years
Southern California Edison
Regulatory Assets [Line Items]
Wildfire Insurance Fund contributions long term	2,849	$ 2,849	2,849		0
Wildfire Insurance Fund contributions current	323	323	323		$ 0
Contributions to Wildfire Insurance Fund	2,400	2,400	2,363	$ 0
Insurance fund liability included in other long-term liabilities	782	782	782
Insurance fund liability included in accounts payable	$ 94	$ 94	$ 94