Commitments and Contingencies (Insurance Recovery) (Details) - 2017/2018 Wildfire/Mudslide Events - USD ($) $ in Millions	12 Months Ended	37 Months Ended
	Dec. 31, 2020	Dec. 31, 2020
Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]
Balance at December 31, 2020	$ 708	$ 708
SCE
Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]
Balance at December 31, 2019	1,710
Insurance recoveries	(1,002)	(1,300)
Balance at December 31, 2020	$ 708	$ 708