Investments (Gains and (Losses) for Equity Securities) (Details) - Southern California Edison - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Investment Holdings [Line Items]
Gross realized gains	$ 51	$ 19	$ 165	$ 64
Gross realized loss	(2)	(1)	(5)	(1)
Net unrealized gains for equity securities	$ 110	$ 3	$ 5	$ 209

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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