Investments (Trust Info) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Investment Holdings [Line Items]
Nuclear decommissioning trusts, net of deferred tax	$ 4,100
SCE
Investment Holdings [Line Items]
Cumulative unrealized holding gains, net of losses	1,900	$ 2,100
Deferred income taxes related to unrealized gains	$ 434	517
Nuclear decommissioning trusts, net of deferred tax		$ 4,400