Compensation and Benefit Plans (Expense Components) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Plans
Pension and Other Postretirement Benefits
Service cost	$ 114	$ 126
Non-service cost
Interest cost	155	141
Other	7	9	$ 10
Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Service cost	30	37	31
Non-service cost
Interest cost	77	80	86
Expected return on plan assets	(111)	(121)	(110)
Settlement costs	0	0	1
Amortization of prior service cost	(1)	(1)	(3)
Amortization of net loss	(17)	0	0
Regulatory adjustment (deferred)	29	24	0
Total non-service benefit	(23)	(18)	(26)
Total expense	7	19	5
SCE
Non-service cost
Total non-service benefit	(70)	(81)	(51)
SCE | Pension Plans
Pension and Other Postretirement Benefits
Service cost	110	121
Non-service cost
Interest cost	138	124
Other	5	6	6
SCE | Postretirement Benefits Other Than Pensions
Pension and Other Postretirement Benefits
Service cost	30	37	31
Non-service cost
Interest cost	77	80	85
Expected return on plan assets	(111)	(122)	(110)
Settlement costs	0	0	1
Amortization of prior service cost	(1)	(1)	(2)
Amortization of net loss	(17)	0	0
Regulatory adjustment (deferred)	29	24	0
Total non-service benefit	(23)	(19)	(26)
Total expense	7	18	5
Continuing Operations | Pension Plans
Pension and Other Postretirement Benefits
Service cost	114	126	138
Non-service cost
Interest cost	155	140	164
Expected return on plan assets	(205)	(228)	(212)
Settlement costs	0	0	6
Amortization of prior service cost	2	3	3
Amortization of net loss	7	9	21
Regulatory adjustment (deferred)	(3)	15	(28)
Total non-service benefit	(44)	(61)	(46)
Total expense recognized	70	65	92
Continuing Operations | SCE | Pension Plans
Pension and Other Postretirement Benefits
Service cost	111	123	133
Non-service cost
Interest cost	143	128	149
Expected return on plan assets	(194)	(214)	(199)
Settlement costs	0	0	0
Amortization of prior service cost	2	3	3
Amortization of net loss	5	6	17
Regulatory adjustment (deferred)	(3)	15	(28)
Total non-service benefit	(47)	(62)	(58)
Total expense recognized	$ 64	$ 61	$ 75