Equity (Schedule of Preferred and Preference Stock) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Edison International's preferred and preference stock of utility		$ 1,901,000,000	$ 2,193,000,000
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%
Shares Outstanding		0
Redemption Price (in dollars per share)	$ 25.50	$ 25.50
Dividends Declared per Share (in dollars per share)		$ 0.757
Preferred stock before issuance costs		$ 0	16,000,000
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%
Shares Outstanding		0
Redemption Price (in dollars per share)	$ 25.80	$ 25.80
Dividends Declared per Share (in dollars per share)		$ 0.786
Preferred stock before issuance costs		$ 0	30,000,000
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%
Shares Outstanding		0
Redemption Price (in dollars per share)	$ 28.75	$ 28.75
Dividends Declared per Share (in dollars per share)		$ 0.801
Preferred stock before issuance costs		$ 0	41,000,000
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%
Shares Outstanding		0
Redemption Price (in dollars per share)	$ 25.80	$ 25.80
Dividends Declared per Share (in dollars per share)		$ 0.886
Preferred stock before issuance costs		0	33,000,000
SCE | Preference stock
Class of Stock [Line Items]
Preferred stock before issuance costs		1,945,000,000	2,245,000,000
Less issuance costs		(44,000,000)	(52,000,000)
Edison International's preferred and preference stock of utility		$ 1,901,000,000	2,193,000,000
SCE | 6.25% Series E (cumulative)
Class of Stock [Line Items]
Preferred Stock, dividend rate, (as a percent)		6.25%
Shares Outstanding		350,000
Redemption Price (in dollars per share)		$ 1,000.00
Dividends Declared per Share (in dollars per share)		$ 62.500
Preferred stock before issuance costs		$ 350,000,000	350,000,000
SCE | 5.10% Series G (cumulative)
Class of Stock [Line Items]
Preferred Stock, dividend rate, (as a percent)		5.10%
Shares Outstanding		88,004
Redemption Price (in dollars per share)		$ 2,500.00
Dividends Declared per Share (in dollars per share)		$ 127.500
Preferred stock before issuance costs		$ 220,000,000	400,000,000
SCE | 5.75% Series H (cumulative)
Class of Stock [Line Items]
Preferred Stock, dividend rate, (as a percent)		5.75%
Shares Outstanding		110,004
Redemption Price (in dollars per share)		$ 2,500.00
Dividends Declared per Share (in dollars per share)		$ 143.750
Preferred stock before issuance costs		$ 275,000,000	275,000,000
SCE | 5.375% Series J (cumulative)
Class of Stock [Line Items]
Preferred Stock, dividend rate, (as a percent)		5.375%
Shares Outstanding		130,004
Redemption Price (in dollars per share)		$ 2,500.00
Dividends Declared per Share (in dollars per share)		$ 134.375
Preferred stock before issuance costs		$ 325,000,000	325,000,000
SCE | 5.45% Series K (cumulative)
Class of Stock [Line Items]
Preferred Stock, dividend rate, (as a percent)		5.45%
Shares Outstanding		120,004
Redemption Price (in dollars per share)		$ 2,500.00
Dividends Declared per Share (in dollars per share)		$ 136.250
Preferred stock before issuance costs		$ 300,000,000	300,000,000
SCE | 5.00% Series L (cumulative)
Class of Stock [Line Items]
Preferred Stock, dividend rate, (as a percent)		5.00%
Shares Outstanding		190,004
Redemption Price (in dollars per share)		$ 2,500.00
Dividends Declared per Share (in dollars per share)		$ 125.000
Preferred stock before issuance costs		$ 475,000,000	$ 475,000,000