Summary of Significant Accounting Policies (Subsequent Events) (Details) - Subsequent event - Senior notes - Recovery bonds - SCE Recovery Funding LLC $ in Millions	Feb. 25, 2021 USD ($)
Subsequent Event [Line Items]
Debt, face amount	$ 338
Due 2033
Subsequent Event [Line Items]
Debt, face amount	$ 138
Interest rate on debt (as a percent)	0.86%
Due 2040
Subsequent Event [Line Items]
Debt, face amount	$ 100
Interest rate on debt (as a percent)	1.94%
Due 2045
Subsequent Event [Line Items]
Debt, face amount	$ 100
Interest rate on debt (as a percent)	2.51%