Compensation and Benefit Plans (Expense Components) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Plans
Pension and Other Postretirement Benefits
Service cost	$ 126.0	$ 137.0
Non-service cost
Interest cost	141.0	164.0
Settlement loss		6.4
Settlement loss, net of tax		3.8
Other	9.0	10.0	$ 10.0
Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Service cost	37.0	31.0	35.0
Non-service cost
Interest cost	80.0	86.0	97.0
Expected return on plan assets	(121.0)	(110.0)	(112.0)
Settlement costs	0.0	1.0	2.0
Amortization of prior service cost	(1.0)	(3.0)	(2.0)
Regulatory adjustment (deferred)	24.0	0.0	0.0
Total non-service benefit	(18.0)	(26.0)	(15.0)
Total expense	19.0	5.0	20.0
SCE
Non-service cost
Total non-service benefit	(81.0)	(51.0)	(35.0)
SCE | Pension Plans
Pension and Other Postretirement Benefits
Service cost	121.0	129.0
Non-service cost
Interest cost	124.0	144.0
Other	6.0	6.0	6.0
SCE | Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Service cost	37.0	31.0	34.0
Non-service cost
Interest cost	80.0	85.0	97.0
Expected return on plan assets	(122.0)	(110.0)	(112.0)
Settlement costs	0.0	1.0	2.0
Amortization of prior service cost	(1.0)	(2.0)	(2.0)
Regulatory adjustment (deferred)	24.0	0.0	0.0
Total non-service benefit	(19.0)	(26.0)	(15.0)
Total expense	18.0	5.0	19.0
Continuing Operations | Pension Plans
Pension and Other Postretirement Benefits
Service cost	126.0	138.0	139.0
Non-service cost
Interest cost	140.0	164.0	172.0
Expected return on plan assets	(228.0)	(212.0)	(220.0)
Settlement costs	0.0	6.0	0.0
Amortization of prior service cost	3.0	3.0	4.0
Amortization of net loss	9.0	21.0	27.0
Regulatory adjustment (deferred)	15.0	(28.0)	(21.0)
Total non-service benefit	(61.0)	(46.0)	(38.0)
Total expense recognized	65.0	92.0	101.0
Continuing Operations | SCE | Pension Plans
Pension and Other Postretirement Benefits
Service cost	123.0	133.0	136.0
Non-service cost
Interest cost	128.0	149.0	156.0
Expected return on plan assets	(214.0)	(199.0)	(205.0)
Settlement costs	0.0	0.0	0.0
Amortization of prior service cost	3.0	3.0	4.0
Amortization of net loss	6.0	17.0	23.0
Regulatory adjustment (deferred)	15.0	(28.0)	(21.0)
Total non-service benefit	(62.0)	(58.0)	(43.0)
Total expense recognized	$ 61.0	$ 75.0	$ 93.0