Revenue (Summary of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 2,987	$ 2,812	$ 5,777	$ 5,636
Accrued unbilled revenue	629		629		$ 488
Southern California Edison
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,878	2,299	5,220	4,758
Alternative revenue programs and other operating revenue	102	501	540	858
Total operating revenue	2,980	2,800	5,760	5,616
Receivables related to contracts from customers	1,300		1,300		1,100
Accrued unbilled revenue	629		629		$ 488
Southern California Edison | Earning Activities
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,658	1,532	3,282	3,034
Alternative revenue programs and other operating revenue	117	5	234	53
Total operating revenue	1,775	1,537	3,516	3,087
Southern California Edison | Cost- Recovery Activities
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,220	767	1,938	1,724
Alternative revenue programs and other operating revenue	(15)	496	306	805
Total operating revenue	$ 1,205	$ 1,263	$ 2,244	$ 2,529