Commitments and Contingencies (Schedule of Estimated Losses) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Charge for wildfire-related claims	$ 4,669	$ 4,669	$ 0
SCE
Loss Contingencies [Line Items]
Charge for wildfire-related claims	4,669	4,669	$ 0
SCE | 2017/2018 Wildfire/Mudslide Events
Loss Contingencies [Line Items]
Charge for wildfire-related claims	4,669	4,669
Expected insurance recoveries	(2,000)	(2,000)
Expected revenue from FERC customers	135	135
Total pre-tax charge	$ 2,500	2,534
Income tax benefit		(709)
Total after-tax charge		$ 1,825