Investments (Trust gain loss) (Details) - SCE - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Investments
Gross realized gains	$ 323	$ 150	$ 339
Gross realized losses	(73)	(127)	(24)
Net unrealized gains/(losses) for equity securities	$ 103	$ (369)	$ 103