Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reconciliation of Unrecognized Tax Benefits
Beginning balance	$ 430	$ 646	$ 613
Tax positions taken during the current year, Increases	66	65	54
Tax positions taken during a prior year, Increases	1	13	0
Tax positions taken during a prior year, decreases	(34)	(294)	(21)
Ending balance	463	430	646
SCE
Reconciliation of Unrecognized Tax Benefits
Beginning balance	418	374	340
Tax positions taken during the current year, Increases	66	65	54
Tax positions taken during a prior year, Increases	0	4	0
Tax positions taken during a prior year, decreases	(27)	(25)	(20)
Ending balance	$ 457	$ 418	$ 374