Summary of Significant Accounting Policies (Allowance) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for long-term uncollectible accounts	$ 34		$ 34		$ 116
SCE
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	353	$ 226	309	$ 188
Included in operation and maintenance expenses in earning activities	22	15	42	25
Included in operation and maintenance expenses in cost-recovery activities	17	28	55	60
Deferred to regulatory memorandum accounts		4	3	6
Less: write-offs, net of recoveries	11	3	28	9
Ending balance	381	270	381	270
Allowance for long-term uncollectible accounts	34		34		$ 116
SCE | Customers
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	337	210	293	175
Included in operation and maintenance expenses in earning activities	20	12	33	18
Included in operation and maintenance expenses in cost-recovery activities	17	28	55	60
Deferred to regulatory memorandum accounts		4	3	6
Less: write-offs, net of recoveries	10		20	5
Ending balance	364	254	364	254
SCE | All others
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	16	16	16	13
Included in operation and maintenance expenses in earning activities	2	3	9	7
Less: write-offs, net of recoveries	1	3	8	4
Ending balance	$ 17	$ 16	$ 17	$ 16