Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Increase (Decrease) in Accumulated Other Comprehensive Loss
Beginning balance	$ (58)
Other comprehensive income (loss), net of tax	(1)		2
Ending Balance	(59)
Accumulated Defined Benefit Plans Adjustment
Increase (Decrease) in Accumulated Other Comprehensive Loss
Beginning balance	(58)		(13)
Other comprehensive loss before reclassifications	(3)		0
Reclassified from accumulated other comprehensive income	2	[1]	2	[1]
Other comprehensive income (loss), net of tax	(1)		2
Ending Balance	(59)		(11)
Southern California Edison
Increase (Decrease) in Accumulated Other Comprehensive Loss
Beginning balance	(28)
Other comprehensive income (loss), net of tax	1		1
Ending Balance	(27)
Southern California Edison | Accumulated Defined Benefit Plans Adjustment
Increase (Decrease) in Accumulated Other Comprehensive Loss
Beginning balance	(28)		(11)
Other comprehensive loss before reclassifications	0		0
Reclassified from accumulated other comprehensive income	1	[1]	1	[1]
Other comprehensive income (loss), net of tax	1		1
Ending Balance	$ (27)		$ (10)

[1] These items are included in the computation of net periodic pension and PBOP expense. See Note 8 for additional information.