Commitments and Contingencies (Wildfire Insurance Recovery) (Details) - SCE $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
Loss Contingencies [Line Items]
Wildfire insurance coverage	$ 1,000
Self insurance	50
2017/2018 Wildfire/Mudslide Events
Loss Contingencies [Line Items]
Wildfire insurance coverage	1,000
Self insurance	10
Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]
Balance beginning	708
Insurance recoveries	(708)
November 2018 - Woolsey Wildfires
Loss Contingencies [Line Items]
Wildfire insurance coverage	1,000
Self insurance	$ 10