Equity (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	May 31, 2020	Sep. 30, 2020	Sep. 30, 2020	May 31, 2019
Class of Stock [Line Items]
Shares issued (in shares)	14,181,882
Proceeds received	$ 800.0
Offering expenses	$ 14.0
Redemption of preferred and preference stock		$ (308.0)
ATM
Class of Stock [Line Items]
Shares issued (in shares)		0	391,501
Proceeds received			$ 27.0
Offering expenses			0.3
Aggregate sales price (up to)				$ 1,500.0
Aggregate sales price remaining		$ 1,300.0	1,300.0
401(k) defined contribution savings plan
Class of Stock [Line Items]
Proceeds received		$ 11.0	$ 83.0
Issuance of new common stock (in shares)		206,900	1,378,700
Stock compensation awards
Class of Stock [Line Items]
Proceeds received		$ 1.0	$ 14.0
Issuance of new common stock (in shares)		4,749	338,442
In lieu of dividend payment
Class of Stock [Line Items]
Proceeds received		$ 4.0	$ 13.0
Issuance of new common stock (in shares)		77,250	206,269
Southern California Edison
Class of Stock [Line Items]
Capital contributions		$ 219.0	$ 1,100.0
Redemption of preferred and preference stock		$ 120.0	$ 308.0
Southern California Edison | 4.32% Series
Class of Stock [Line Items]
Security dividend rate, (as a percent)		4.32%
Redemption price (in dollars per share)		$ 28.75	$ 28.75
Southern California Edison | 4.08% Series
Class of Stock [Line Items]
Security dividend rate, (as a percent)		4.08%
Redemption price (in dollars per share)		$ 25.50	25.50
Southern California Edison | 4.24% Series
Class of Stock [Line Items]
Security dividend rate, (as a percent)		4.24%
Redemption price (in dollars per share)		$ 25.80	25.80
Southern California Edison | 4.78% Series
Class of Stock [Line Items]
Security dividend rate, (as a percent)		4.78%
Redemption price (in dollars per share)		$ 25.80	$ 25.80
Southern California Edison | Series G Preferred Stock
Class of Stock [Line Items]
Redemption of preferred and preference stock		$ 180.0
Redemption Premium		$ 15.0