Preferred and Preference Stock of Utility (Textual) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Preferred and Preference Stock
Preferred and Preference Stock of Utility
Dividends payable	$ 12	$ 12	$ 14
SCE | Cumulative preferred stock $100 par value
Preferred and Preference Stock of Utility
Preferred stock, par value (in dollars per share)	$ 100
Preferred stock, shares authorized	12,000,000
SCE | Cumulative preferred stock $25 par value
Preferred and Preference Stock of Utility
Preferred stock, par value (in dollars per share)	$ 25
Preferred stock, shares authorized	24,000,000
SCE | No par value
Preferred and Preference Stock of Utility
Preferred stock, shares authorized	50,000,000
SCE | Preferred and Preference Stock
Preferred and Preference Stock of Utility
Preferred stock, shares issued	0	0	0
Preferred stock, shares redeemed	0	0	0
Dividends payable	$ 12	$ 12	$ 14
SCE | 5.00% Series L (cumulative)
Preferred and Preference Stock of Utility
Issuance of preference stock, during the period, value	$ 475