Investments (Gains and (Losses) for Equity Securities) (Details) - Southern California Edison - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Investment Holdings [Line Items]
Gross realized gains	$ 75	$ 22	$ 114	$ 45
Gross realized loss	1	0	3	0
Net unrealized gains (losses) for equity securities	$ 271	$ 38	$ (105)	$ 206