Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (54)	$ (59)	$ (56)	$ (58)
Pension and PBOP – net loss:
Ending Balance	(53)	(56)	(53)	(56)
Accumulated Other Comprehensive Loss | Southern California Edison
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(21)	(27)	(22)	(28)
Pension and PBOP – net loss:
Ending Balance	(20)	(26)	(20)	(26)
Accumulated Defined Benefit Plans Adjustment
Pension and PBOP – net loss:
Other comprehensive loss before reclassifications	0	(1)	0	(4)
Reclassified from accumulated other comprehensive loss	1	4	3	6
Change	1	3	3	2
Accumulated Defined Benefit Plans Adjustment | Southern California Edison
Pension and PBOP – net loss:
Other comprehensive loss before reclassifications	0	(1)	0	(1)
Reclassified from accumulated other comprehensive loss	1	2	2	3
Change	$ 1	$ 1	$ 2	$ 2