Leases (Lease Expense) (Details) - SCE - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lessee, Lease, Description [Line Items]
Total lease cost	$ 1,041	$ 723	$ 2,397	$ 1,693
PPA Operating Leases
Lessee, Lease, Description [Line Items]
Operating lease cost	136	35	199	74
Finance lease cost		1		2
Variable lease cost	893	676	2,163	1,582
Total lease cost	1,029	712	2,362	1,658
Other Operating Leases
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 12	$ 11	$ 35	$ 35