Equity (Preferred and Preference Stock of Utility) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Redemption of preferred and preference stock		$ 308
5.10% Series G (cumulative) | SCE
Class of Stock [Line Items]
Redemption of preferred and preference stock	$ 180
Redemption premium	6
SCE
Class of Stock [Line Items]
Redemption of preferred and preference stock	$ 120	$ 308
SCE | Cumulative preferred stock $100 par value
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)		$ 100
Preferred stock, shares authorized		12,000,000
SCE | Cumulative preferred stock $25 par value
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)		$ 25
Preferred stock, shares authorized		24,000,000
SCE | No par value
Class of Stock [Line Items]
Preferred stock, shares authorized		50,000,000
SCE | 4.32% Series
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)		$ 25
Preferred Stock, dividend rate, (as a percent)	4.32%	4.32%
Redemption Price (in dollars per share)	$ 28.75	$ 28.75
SCE | 4.08% Series
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)		$ 25
Preferred Stock, dividend rate, (as a percent)	4.08%	4.08%
Redemption Price (in dollars per share)	$ 25.50	$ 25.50
SCE | 4.24% Series
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)		$ 25
Preferred Stock, dividend rate, (as a percent)	4.24%	4.24%
Redemption Price (in dollars per share)	$ 25.80	$ 25.80
SCE | 4.78% Series
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)		$ 25
Preferred Stock, dividend rate, (as a percent)	4.78%	4.78%
Redemption Price (in dollars per share)	$ 25.80	$ 25.80
SCE | Preference stock
Class of Stock [Line Items]
Shares issued (in shares)			0	0
SCE | 5.10% Series G (cumulative)
Class of Stock [Line Items]
Preferred Stock, dividend rate, (as a percent)		5.10%
Redemption Price (in dollars per share)		$ 2,500.00
Redemption premium	$ 9