Commitments and Contingencies (Wildfire Insurance Recovery) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Jun. 30, 2021
2017/2018 Wildfire/Mudslide Events
Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]
Balance ending	$ 666
SCE
Loss Contingencies [Line Items]
Wildfire insurance coverage		$ 1,000
Self insurance		$ 50
SCE | 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	(42)
Balance ending	666
SCE | December 2017 - Thomas and Koenigstein Wildfires
Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]
Balance ending	0
SCE | November 2018 - Woolsey Wildfires
Loss Contingencies [Line Items]
Wildfire insurance coverage	1,000
Self insurance	10
Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]
Balance ending	$ 666