Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension and PBOP – net gain (loss):
Other	$ 1	$ 0	$ 2
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(56)	(58)
Pension and PBOP – net gain (loss):
Ending balance	(53)	(56)	(58)
Accumulated Defined Benefit Plans Adjustment
Pension and PBOP – net gain (loss):
Other comprehensive (loss) income before reclassifications	(4)	(8)
Reclassified from accumulated other comprehensive loss	6	10
Other	1	0
Change	3	2
SCE
Pension and PBOP – net gain (loss):
Other	1	0	2
SCE | Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(22)	(28)
Pension and PBOP – net gain (loss):
Ending balance	(20)	(22)	$ (28)
SCE | Accumulated Defined Benefit Plans Adjustment
Pension and PBOP – net gain (loss):
Other comprehensive (loss) income before reclassifications	(2)	1
Reclassified from accumulated other comprehensive loss	3	5
Other	1	0
Change	$ 2	$ 6