Compensation and Benefit Plans (Plan Assets and Benefit Obligation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amounts recognized in the consolidated balance sheets consist of:
Long-term liabilities	$ (563)	$ (674)
Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	4,139	3,880
Service cost	121	114
Interest cost	124	155
Actuarial (gain) loss	323	240
Benefits paid	(231)	(250)
Projected benefit obligation at end of year	4,476	4,139	$ 3,880
Change in plan assets
Fair value of plan assets at beginning of year	3,755	3,321
Actual return on plan assets	584	611
Employer contributions	62	73
Benefits paid	(230)	(250)
Fair value of plan assets at end of year	4,171	3,755	$ 3,321
Funded status at end of year	(305)	(384)
Amounts recognized in the consolidated balance sheets consist of:
Current liabilities	(24)	(19)
Long-term liabilities	(281)	(365)
Amounts recognized in the consolidated balance sheets	(305)	(384)
Amounts recognized in accumulated other comprehensive loss consist of:
Prior service cost	(1)	(1)
Net loss	96	95
Total amounts recognized in accumulated other comprehensive loss	95	94
Amounts recognized as a regulatory asset (liability)	12	87
Total not yet recognized as income	107	181
Accumulated benefit obligation at end of year	4,238	3,968
Pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	4,476	4,139
Accumulated benefit obligation	4,238	3,968
Fair value of plan assets	$ 4,171	$ 3,755
Weighted average assumptions used to determine obligations at end of year:
Discount rate	2.38%	3.11%	4.19%
Rate of compensation increase	4.00%	4.10%
Gain (loss) from increase in discount rate	$ (339)	$ 401
Gains from other economic assumption changes	(117)	(157)
Pension Plans | Edison International Parent
Weighted average assumptions used to determine obligations at end of year:
Long-term payable	139	133
PBOP
Change in projected benefit obligation
Projected benefit obligation at beginning of year	2,083	1,986
Service cost	38	30	$ 37
Interest cost	63	77	80
Actuarial (gain) loss	(46)	70
Plan participants' contributions	29	29
Benefits paid	(94)	(109)
Projected benefit obligation at end of year	2,073	2,083	1,986
Change in plan assets
Fair value of plan assets at beginning of year	2,465	2,133
Actual return on plan assets	309	401
Employer contributions	8	11
Plan participants' contributions	29	29
Benefits paid	(94)	(109)
Fair value of plan assets at end of year	2,717	2,465	2,133
Funded status at end of year	644	382
Amounts recognized in the consolidated balance sheets consist of:
Long-term assets	663	393
Current liabilities	(10)	(11)
Long-term liabilities	(9)	0
Amounts recognized in the consolidated balance sheets	644	382
Amounts recognized in accumulated other comprehensive loss consist of:
Net loss	1	2
Amounts recognized as a regulatory asset (liability)	(671)	(416)
Total not yet recognized as income	$ (670)	$ (414)
Weighted average assumptions used to determine obligations at end of year:
Discount rate	2.67%	3.32%
Rate assumed for following year	6.50%	6.50%
Ultimate rate	5.00%	5.00%
SCE
Amounts recognized in the consolidated balance sheets consist of:
Long-term liabilities	$ (144)	$ (237)
SCE | Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	3,662	3,431
Service cost	117	110
Interest cost	110	138
Actuarial (gain) loss	292	199
Benefits paid	(197)	(216)
Projected benefit obligation at end of year	3,984	3,662	3,431
Change in plan assets
Fair value of plan assets at beginning of year	3,541	3,124
Actual return on plan assets	551	576
Employer contributions	45	57
Benefits paid	(197)	(216)
Fair value of plan assets at end of year	3,940	3,541	3,124
Funded status at end of year	(44)	(121)
Amounts recognized in the consolidated balance sheets consist of:
Current liabilities	(2)	(2)
Long-term liabilities	(42)	(119)
Amounts recognized in the consolidated balance sheets	(44)	(121)
Amounts recognized in accumulated other comprehensive loss consist of:
Prior service cost	0	0
Net loss	16	17
Total amounts recognized in accumulated other comprehensive loss	16	17
Amounts recognized as a regulatory asset (liability)	12	87
Total not yet recognized as income	28	104
Accumulated benefit obligation at end of year	3,776	3,529
Pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	3,984	3,662
Accumulated benefit obligation	3,776	3,529
Fair value of plan assets	$ 3,940	$ 3,541
Weighted average assumptions used to determine obligations at end of year:
Discount rate	2.38%	3.11%
Rate of compensation increase	4.00%	4.10%
Net loss reclassified from other comprehensive loss	$ 41	$ 37
Gain (loss) from increase in discount rate	(305)	373
Gains from other economic assumption changes	(124)	(177)
SCE | PBOP
Change in projected benefit obligation
Projected benefit obligation at beginning of year	2,074	1,977
Service cost	37	30	37
Interest cost	63	77	80
Actuarial (gain) loss	(45)	70
Plan participants' contributions	29	29
Benefits paid	(94)	(109)
Projected benefit obligation at end of year	2,064	2,074	1,977
Change in plan assets
Fair value of plan assets at beginning of year	2,464	2,133
Actual return on plan assets	309	401
Employer contributions	8	10
Plan participants' contributions	29	29
Benefits paid	(93)	(109)
Fair value of plan assets at end of year	2,717	2,464	$ 2,133
Funded status at end of year	653	390
Amounts recognized in the consolidated balance sheets consist of:
Long-term assets	663	402
Current liabilities	(10)	(12)
Long-term liabilities	0	0
Amounts recognized in the consolidated balance sheets	653	390
Amounts recognized in accumulated other comprehensive loss consist of:
Net loss	0	0
Amounts recognized as a regulatory asset (liability)	(671)	(416)
Total not yet recognized as income	$ (671)	$ (416)
Weighted average assumptions used to determine obligations at end of year:
Discount rate	2.67%	3.32%
Rate assumed for following year	6.50%	6.50%
Ultimate rate	5.00%	5.00%