Compensation and Benefit Plans (Plan Assets and Benefit Obligation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized in the consolidated balance sheets consist of:
Long-term liabilities	$ (674)	$ (869)
SCE
Amounts recognized in the consolidated balance sheets consist of:
Long-term liabilities	(237)	(433)
Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year	3,880	4,179
Service cost	114	126
Interest cost	155	141
Actuarial (gain) loss	240	(280)
Benefits paid	(250)	(286)
Projected benefit obligation at end of year	4,139	3,880	$ 4,179
Change in plan assets
Fair value of plan assets at beginning of year	3,321	3,616
Actual return on plan assets	611	(86)
Employer contributions	73	77
Benefits paid	(250)	(286)
Fair value of plan assets at end of year	3,755	3,321	$ 3,616
Funded status at end of year	(384)	(559)
Amounts recognized in the consolidated balance sheets consist of:
Long-term assets	0	2
Current liabilities	(19)	(29)
Long-term liabilities	(365)	(532)
Amounts recognized in the consolidated balance sheets	(384)	(559)
Amounts recognized in accumulated other comprehensive loss consist of:
Prior service cost	(1)	(1)
Net loss	95	83
Total amounts recognized in accumulated other comprehensive loss	94	82
Amounts recognized as a regulatory liability	87	271
Total not yet recognized as income	181	353
Accumulated benefit obligation at end of year	3,968	3,753
Pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	4,139	3,880
Accumulated benefit obligation	3,968	3,753
Fair value of plan assets	$ 3,755	$ 3,321
Weighted average assumptions used to determine obligations at end of year:
Discount rate	3.11%	4.19%	3.46%
Rate of compensation increase	4.10%	4.10%
Assumed health care cost trend rates:
Gain (loss) from increase in discount rate	$ (401)	$ (277)
Gains from other economic assumption changes	(157)
Pension Plans | Edison International
Assumed health care cost trend rates:
Long-term payable	133	117
Pension Plans | SCE
Change in projected benefit obligation
Projected benefit obligation at beginning of year	3,431	3,702
Service cost	110	121
Interest cost	138	124
Actuarial (gain) loss	199	(273)
Benefits paid	(216)	(243)
Projected benefit obligation at end of year	3,662	3,431	$ 3,702
Change in plan assets
Fair value of plan assets at beginning of year	3,124	3,390
Actual return on plan assets	576	(86)
Employer contributions	57	52
Benefits paid	(216)	(232)
Fair value of plan assets at end of year	3,541	3,124	3,390
Funded status at end of year	(121)	(307)
Amounts recognized in the consolidated balance sheets consist of:
Long-term assets	0	0
Current liabilities	(2)	(5)
Long-term liabilities	(119)	(302)
Amounts recognized in the consolidated balance sheets	(121)	(307)
Amounts recognized in accumulated other comprehensive loss consist of:
Prior service cost	0	0
Net loss	17	17
Total amounts recognized in accumulated other comprehensive loss	17	17
Amounts recognized as a regulatory liability	87	271
Total not yet recognized as income	104	288
Accumulated benefit obligation at end of year	3,529	3,342
Pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	3,662	3,431
Accumulated benefit obligation	3,529	3,342
Fair value of plan assets	$ 3,541	$ 3,124
Weighted average assumptions used to determine obligations at end of year:
Discount rate	3.11%	4.19%
Rate of compensation increase	4.10%	4.10%
Assumed health care cost trend rates:
Gain (loss) from increase in discount rate	$ (373)	$ (261)
Gains from other economic assumption changes	(177)
Net loss reclassified from other comprehensive loss	37	21
Postretirement Benefits Other Than Pensions
Change in projected benefit obligation
Projected benefit obligation at beginning of year	1,986	2,337
Service cost	30	37	31
Interest cost	77	80	86
Actuarial (gain) loss	70	(382)
Plan participants' contributions	29	28
Benefits paid	(109)	(114)
Projected benefit obligation at end of year	2,083	1,986	2,337
Change in plan assets
Fair value of plan assets at beginning of year	2,133	2,330
Actual return on plan assets	401	(123)
Employer contributions	11	13
Plan participants' contributions	29	28
Benefits paid	(109)	(115)
Fair value of plan assets at end of year	2,465	2,133	$ 2,330
Funded status at end of year	382	147
Amounts recognized in the consolidated balance sheets consist of:
Long-term assets	393	159
Current liabilities	(11)	(12)
Long-term liabilities	0	0
Amounts recognized in the consolidated balance sheets	382	147
Amounts recognized in accumulated other comprehensive loss consist of:
Net loss	2	1
Amounts recognized as a regulatory liability	(416)	(185)
Total not yet recognized as income	$ (414)	$ (184)
Weighted average assumptions used to determine obligations at end of year:
Discount rate	3.32%	4.35%	3.70%
Assumed health care cost trend rates:
Rate assumed for following year	6.50%	6.75%
Ultimate rate	5.00%	5.00%
Gain (loss) from increase in discount rate	$ (195)
Experience gain	137
Postretirement Benefits Other Than Pensions | SCE
Change in projected benefit obligation
Projected benefit obligation at beginning of year	1,977	$ 2,325
Service cost	30	37	$ 31
Interest cost	77	80	85
Actuarial (gain) loss	70	(379)
Plan participants' contributions	29	28
Benefits paid	(109)	(114)
Projected benefit obligation at end of year	2,074	1,977	2,325
Change in plan assets
Fair value of plan assets at beginning of year	2,133	2,330
Actual return on plan assets	401	(123)
Employer contributions	10	12
Plan participants' contributions	29	28
Benefits paid	(109)	(114)
Fair value of plan assets at end of year	2,464	2,133	$ 2,330
Funded status at end of year	390	156
Amounts recognized in the consolidated balance sheets consist of:
Long-term assets	402	168
Current liabilities	(12)	(12)
Long-term liabilities	0	0
Amounts recognized in the consolidated balance sheets	390	156
Amounts recognized in accumulated other comprehensive loss consist of:
Net loss	0	0
Amounts recognized as a regulatory liability	(416)	(185)
Total not yet recognized as income	$ (416)	$ (185)
Weighted average assumptions used to determine obligations at end of year:
Discount rate	3.32%	4.35%
Assumed health care cost trend rates:
Rate assumed for following year	6.50%	6.75%
Ultimate rate	5.00%	5.00%
Gain (loss) from increase in discount rate	$ (194)
Experience gain	$ 135