Revenue (Summary of Revenue) (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended
	Jul. 31, 2021	Jul. 31, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total operating revenue			$ 3,315	$ 2,987	$ 6,275	$ 5,777
SCE
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers			3,126	2,878	6,025	5,220
Alternative revenue programs and other operating revenue			180	102	234	540
Total operating revenue			3,306	2,980	6,259	5,760
Receivables from contracts with customers			2,100		2,100		$ 1,500
Accrued unbilled revenues			863		863		$ 521
Revenue recovery period		2 years
SCE | West of Devers
Disaggregation of Revenue [Line Items]
Proceeds from external investment	$ 400
Revenue recovery period	30 years
SCE | Earning Activities
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers			1,703	1,658	3,407	3,282
Alternative revenue programs and other operating revenue			127	117	190	234
Total operating revenue			1,830	1,775	3,597	3,516
SCE | Cost- Recovery Activities
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers			1,423	1,220	2,618	1,938
Alternative revenue programs and other operating revenue			53	(15)	44	306
Total operating revenue			$ 1,476	$ 1,205	$ 2,662	$ 2,244