Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Increase (Decrease) in Accumulated Other Comprehensive Income
Balance at the beginning of period	$ (139)	$ (76)
Current period change	52	(63)	(113)
Balance at the end of period	(87)	(139)	(76)
Unrealized Gain (Loss) on Cash Flow Hedges
Increase (Decrease) in Accumulated Other Comprehensive Income
Balance at the beginning of period	(34)	16
Current period change	34	(50)
Balance at the end of period	0	(34)
Pension and PBOP – Net Loss
Increase (Decrease) in Accumulated Other Comprehensive Income
Balance at the beginning of period	(100)	(87)
Current period change	13	(13)
Balance at the end of period	(87)	(100)
Pension and PBOP – Prior Service Cost
Increase (Decrease) in Accumulated Other Comprehensive Income
Balance at the beginning of period	(5)	(5)
Current period change	5	0
Balance at the end of period	0	(5)
Southern California Edison
Increase (Decrease) in Accumulated Other Comprehensive Income
Balance at the beginning of period	(24)	(25)
Current period change	(5)	1	(6)
Balance at the end of period	(29)	(24)	(25)
Southern California Edison | Pension and PBOP – Net Loss
Increase (Decrease) in Accumulated Other Comprehensive Income
Balance at the beginning of period	(24)	(25)
Current period change	(5)	1
Balance at the end of period	(29)	(24)
Southern California Edison | Pension and PBOP – Prior Service Cost
Increase (Decrease) in Accumulated Other Comprehensive Income
Balance at the beginning of period	0	0
Current period change	0	0
Balance at the end of period	$ 0	$ 0