Leases (Summary of Other Information) (Details) - SCE - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities:
PPA operating leases	$ 463	$ 0
PPA finance leases, weighted average remaining lease term (in years)	16 years 8 months 1 day	11 years 6 months 3 days
PPA finance leases, weighted average discount rate	11.29%	8.76%
PPA Operating Leases
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 111	$ 118
Financing cash flows from PPA finance leases	$ 1	$ 1
Weighted average remaining lease term (in years)	9 years 9 months	16 years 18 days
Weighted average discount rate	3.12%	4.46%
Other Operating Leases
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 44	$ 44
Other operating leases	$ 58	$ 34
Weighted average remaining lease term (in years)	12 years 1 month 17 days	12 years 8 months 23 days
Weighted average discount rate	3.63%	3.88%