Summary of Significant Accounting Policies (Allowance) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Credit Loss Roll Forward
Wildfire Insurance Fund expense	$ 36	$ 52
Wildfire Insurance Fund
Credit Loss Roll Forward
Insurance fund contribution amortization period	20 years		15 years
SCE
Credit Loss Roll Forward
Beginning balance	$ 364	354	$ 354
Current period provision for uncollectible accounts	61	20
Write-offs, net of recoveries	(62)	(30)
Ending balance	363	344	364
Recovery from customers, incremental costs	50	14
Allowance for long-term credit losses	22		4
Wildfire Insurance Fund expense	36	52
SCE | Customers
Credit Loss Roll Forward
Beginning balance	347	334	334
Current period provision for uncollectible accounts	60	20
Write-offs, net of recoveries	(60)	(28)
Ending balance	347	326	347
SCE | All others
Credit Loss Roll Forward
Beginning balance	17	20	20
Current period provision for uncollectible accounts	1
Write-offs, net of recoveries	(2)	(2)
Ending balance	$ 16	$ 18	$ 17