Compensation and Benefit Plans (Changes in Plan Assets and Benefits Obligations Recognized in OCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Unrecognized net loss to be amortized	$ (3)
Unrecognized prior service cost (credit) to be amortized	(1)
Pension Plans
Pension and Other Postretirement Benefits
Net loss	5	$ 0	$ 6
Settlement charges	0	(6)	0
Amortization of net loss	(9)	(10)	(10)
Total recognized in other comprehensive loss	(4)	(16)	(4)
Total recognized in expense and other comprehensive loss	61	76	97
Unrecognized net loss to be amortized	8
Unrecognized prior service cost (credit) to be amortized	2
Amount of net loss expected to be reclassified from other comprehensive loss	8
SCE | Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Unrecognized net loss to be amortized	(3)
Unrecognized prior service cost (credit) to be amortized	(1)
SCE | Pension Plans
Pension and Other Postretirement Benefits
Net loss	5	3	4
Settlement charges	0	0	0
Amortization of net loss	(6)	(6)	(6)
Total recognized in other comprehensive loss	(1)	(3)	(2)
Total recognized in expense and other comprehensive loss	60	$ 72	$ 91
Unrecognized net loss to be amortized	6
Unrecognized prior service cost (credit) to be amortized	2
Amount of net loss expected to be reclassified from other comprehensive loss	$ 6