Summary of Significant Accounting Policies (Allowance) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for long-term uncollectible accounts	$ 35		$ 35		$ 116
SCE
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	381	$ 270	309	$ 188
Included in operation and maintenance expenses in earning activities	14	13	56	38
Included in operation and maintenance expenses in cost-recovery activities	57	52	112	112
Deferred to regulatory memorandum accounts		7	3	13
Less: write-offs, net of recoveries	26	4	54	13
Ending balance	426	338	426	338
Allowance for long-term uncollectible accounts	35		35		$ 116
SCE | Customers
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	364	254	293	175
Included in operation and maintenance expenses in earning activities	12	9	45	27
Included in operation and maintenance expenses in cost-recovery activities	57	52	112	112
Deferred to regulatory memorandum accounts		7	3	13
Less: write-offs, net of recoveries	24	1	44	6
Ending balance	409	321	409	321
SCE | All others
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	17	16	16	13
Included in operation and maintenance expenses in earning activities	2	4	11	11
Less: write-offs, net of recoveries	2	3	10	7
Ending balance	$ 17	$ 17	$ 17	$ 17