Property, Plant and Equipment (Textual) (Details) (Southern California Edison, USD $)	12 Months Ended				12 Months Ended		1 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Oct. 02, 2012	Dec. 31, 2012 Minimum Capitalized Software Costs	Dec. 31, 2012 Maximum Capitalized Software Costs	Nov. 30, 2010 Four Corners Unit 4 And 5 (coal)
Property, Plant and Equipment [Line Items]
Estimated Useful Lives					5 years	15 years
Capitalized software costs	$ 1,500,000,000	$ 1,400,000,000
Capitalized software, accumulated amortization	651,000,000	491,000,000
Capitalized software, amortization expense	217,000,000	156,000,000	129,000,000
Capitalized software, estimated amortization expense 2013 through 2017	207,000,000
Monthly sales price reduction for sale closing after October 1, 2012				7,500,000
Sale price of investment in facility							$ 294,000,000