Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1,	$ 370	$ 338
Tax positions taken during the current year, Increases	38	32
Tax positions taken during a prior year, Increases	273	0
Tax positions taken during a prior year, Decreases	(18)	(11)
Balance at September 30,	663	359
Unrecognized tax benefits that would impact the effective tax rate	446
Southern California Edison
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1,	282	249
Tax positions taken during the current year, Increases	39	32
Tax positions taken during a prior year, Increases	4	0
Tax positions taken during a prior year, Decreases	(21)	(11)
Balance at September 30,	304	$ 270
Unrecognized tax benefits that would impact the effective tax rate	$ 87