Summary of Significant Accounting Policies - Amortization of Deferred Financing Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Regulatory Assets
Amortization of deferred financing costs charged to interest expense	$ 41	$ 39	$ 37
SCE
Regulatory Assets
Amortization of deferred financing costs charged to interest expense	$ 34	$ 32	$ 31