Preferred and Preference Stock of Utility (Textual) (Details) (Southern California Edison, USD $) In Millions, except Share data, unless otherwise specified				12 Months Ended							1 Months Ended
	Dec. 31, 2012 Cumulative preferred stock 100 dollars par value	Dec. 31, 2012 Cumulative preferred stock 25 dollars par value	Dec. 31, 2012 Preference stock, no par value	Dec. 31, 2012 4.32% Series A (variable and noncumulative)	Dec. 31, 2012 6.50% Series D (cumulative)	Dec. 31, 2012 6.25% Series E (cumulative)	Dec. 31, 2012 5.625% Series F (cumulative)	Dec. 31, 2012 Preferred Stock and Preference Stock	Jan. 31, 2013 Series G Preferred Stock Subsequent Event	Jan. 31, 2013 SCE Trust II Series G Preferred Stock Subsequent Event	Jan. 31, 2013 SCE Trust II Trust Securities	Jan. 31, 2013 SCE Trust II Trust Securities Subsequent Event
Preferred and Preference Stock of Utility
Preferred stock stated value per share (in dollars per share)	$ 100	$ 25
Preferred stock shares authorized (shares)	12,000,000	24,000,000	50,000,000
Redemption price (in dollars per share)				$ 100	$ 100	$ 1,000	$ 2,500
Stock redeemed and retired				$ 75
Dividends payable								$ 24
Shares issued (in shares)									160,004
Preference stock (as a percent)				4.32%	6.50%	6.25%	5.625%				5.10%	5.10%
Liquidation value (in dollars per share)									$ 2,500	$ 2,500		$ 25