Compensation and Benefit Plans (Expense Components) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Plans
Pension and Other Postretirement Benefits [Line Items]
Service cost	$ 121	$ 114
Non-service cost
Interest cost	124	155
PBOP
Pension and Other Postretirement Benefits [Line Items]
Service cost	38	30	$ 37
Non-service cost
Interest cost	63	77	80
Expected return on plan assets	(119)	(111)	(121)
Amortization of prior service cost	(1)	(1)	(1)
Amortization of net (gain) loss	(29)	(17)	0
Regulatory adjustment (deferred)	(49)	(29)	(24)
Total non-service benefit	(37)	(23)	(18)
Total expense	1	7	19
SCE
Non-service cost
Total non-service benefit	(102)	(70)	(81)
SCE | Pension Plans
Pension and Other Postretirement Benefits [Line Items]
Service cost	117	110
Non-service cost
Interest cost	110	138
SCE | PBOP
Pension and Other Postretirement Benefits [Line Items]
Service cost	37	30	37
Non-service cost
Interest cost	63	77	80
Expected return on plan assets	(119)	(111)	(122)
Amortization of prior service cost	(1)	(1)	(1)
Amortization of net (gain) loss	(29)	(17)	0
Regulatory adjustment (deferred)	(49)	(29)	(24)
Total non-service benefit	(37)	(23)	(19)
Total expense	0	7	18
Continuing Operations | Pension Plans
Pension and Other Postretirement Benefits [Line Items]
Service cost	121	114	126
Non-service cost
Interest cost	124	155	140
Expected return on plan assets	(215)	(205)	(228)
Amortization of prior service cost	2	2	3
Amortization of net (gain) loss	10	7	9
Regulatory adjustment (deferred)	16	(3)	15
Total non-service benefit	(63)	(44)	(61)
Total expense recognized	58	70	65
Continuing Operations | SCE | Pension Plans
Pension and Other Postretirement Benefits [Line Items]
Service cost	119	111	123
Non-service cost
Interest cost	114	143	128
Expected return on plan assets	(203)	(194)	(214)
Amortization of prior service cost	1	2	3
Amortization of net (gain) loss	7	5	6
Regulatory adjustment (deferred)	16	(3)	15
Total non-service benefit	(65)	(47)	(62)
Total expense recognized	$ 54	$ 64	$ 61