Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Increase (Decrease) in Accumulated Other Comprehensive Loss
Beginning balance	$ (56)
Other comprehensive income (loss), net of tax	2	$ (1)
Ending Balance	(54)
Accumulated Defined Benefit Plans Adjustment
Increase (Decrease) in Accumulated Other Comprehensive Loss
Beginning balance	(56)	(58)
Other comprehensive loss before reclassifications	0	(3)
Reclassified from accumulated other comprehensive income	2	2
Other comprehensive income (loss), net of tax	2	(1)
Ending Balance	(54)	(59)
Southern California Edison
Increase (Decrease) in Accumulated Other Comprehensive Loss
Beginning balance	(22)
Other comprehensive income (loss), net of tax	1	1
Ending Balance	(21)
Southern California Edison | Accumulated Defined Benefit Plans Adjustment
Increase (Decrease) in Accumulated Other Comprehensive Loss
Beginning balance	(22)	(28)
Other comprehensive loss before reclassifications	0	0
Reclassified from accumulated other comprehensive income	1	1
Other comprehensive income (loss), net of tax	1	1
Ending Balance	$ (21)	$ (27)