Compensation and Benefit Plans (Changes in Plan Assets and Benefits Obligations Recognized in OCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Unrecognized prior service cost (credit) to be amortized	$ (2)
Pension Plans
Pension and Other Postretirement Benefits
Net loss (gain)	6	$ 7	$ 85
Amortization of net loss and other	(10)	(15)	(13)
Total recognized in other comprehensive loss	(4)	(8)	72
Total recognized in expense and other comprehensive loss	97	110	223
Unrecognized net loss to be amortized	19
Unrecognized prior service cost (credit) to be amortized	3
Amount of net loss expected to be reclassified from other comprehensive loss	10
SCE | Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Unrecognized prior service cost (credit) to be amortized	(2)
SCE | Pension Plans
Pension and Other Postretirement Benefits
Net loss (gain)	4	(9)	37
Amortization of net loss and other	(6)	(9)	(4)
Total recognized in other comprehensive loss	(2)	(18)	33
Total recognized in expense and other comprehensive loss	91	$ 93	$ 174
Unrecognized net loss to be amortized	15
Unrecognized prior service cost (credit) to be amortized	3
Amount of net loss expected to be reclassified from other comprehensive loss	$ 6