Compensation and Benefit Plans (Unrecognized Compensation Costs) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		12 Months Ended			12 Months Ended
	Dec. 31, 2012 Employee Stock Option	Dec. 31, 2012 Restricted Stock Units (RSUs)	Dec. 31, 2011 Performance Shares	Dec. 31, 2012 Southern California Edison Employee Stock Option	Dec. 31, 2012 Southern California Edison Restricted Stock Units (RSUs)	Dec. 31, 2011 Southern California Edison Performance Shares
Pension and Other Postretirement Benefits
Unrecognized compensation cost, net of expected forfeitures	$ 14	$ 6	$ 4	$ 11	$ 4	$ 2
Cost to be recognized in 2013		4			3
Cost to be recognized in 2014		$ 2			$ 1
Weighed-average period (in years)	2 years		2 years	2 years		2 years