Leases (Summary of Lease Expense Components) (Details) - SCE $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Total lease cost	$ 2,252
PPA Operating Leases
Lessee, Lease, Description [Line Items]
Lease cost	118
Finance lease cost	1
Variable lease cost	2,087
Total lease cost	2,206
Other Operating Leases
Lessee, Lease, Description [Line Items]
Lease cost	$ 46