Compensation and Benefit Plans (Plan Assets and Benefit Obligation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Aug. 31, 2014
Change in projected benefit obligation
Actuarial (gain) loss		$ 374
Amounts recognized in the consolidated balance sheets consist of1:
Long-term liabilities	$ (1,759)	(2,155)
Weighted-average assumptions used to determine obligations at end of year:
Defined Benefit Plan, Accumulated Other Comprehensive Income Net Gains (Losses), after Tax	0	(3)
Southern California Edison
Change in projected benefit obligation
Actuarial (gain) loss		357
Amounts recognized in the consolidated balance sheets consist of1:
Long-term liabilities	(1,284)	(1,672)
Pension Plans
Change in projected benefit obligation
Benefit obligation at beginning of year	4,517	4,178
Service cost	142	133
Interest cost	170	181
Actuarial (gain) loss	(149)	469
Curtailment gain	0	(5)
Benefits paid	(305)	(449)
Other	(1)	10
Benefit obligation at beginning of year	4,374	4,517	$ 4,178
Change in plan assets
Fair value of plan assets at beginning of year	3,454	3,477
Actual return on plan assets	30	257
Employer contributions	119	169
Benefits paid	(305)	(449)
Fair value of plan assets at end of year	3,298	3,454	$ 3,477
Funded status at end of year	(1,076)	(1,063)
Amounts recognized in the consolidated balance sheets consist of1:
Current liabilities	(27)	(27)
Long-term liabilities	(1,049)	(1,036)
Total liabilities	(1,076)	(1,063)
Amounts recognized in accumulated other comprehensive loss consist of:
Net loss1	96	102
Amounts recognized in accumulated other comprehensive loss consist of:
Prior service cost	15	20
Net loss	660	640
Total amounts recognized as regulatory asset	675	660
Total not yet recognized as expense	771	762
Accumulated benefit obligation at end of year	4,200	4,356
Pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	4,374	4,517
Accumulated benefit obligation	4,200	4,356
Fair value of plan assets	$ 3,298	$ 3,454
Weighted-average assumptions used to determine obligations at end of year:
Discount rate	4.18%	3.85%	4.75%	4.00%
Rate of compensation increase	4.00%	4.00%
Pension Plans | Southern California Edison
Change in projected benefit obligation
Benefit obligation at beginning of year	$ 3,999	$ 3,721
Service cost	133	124
Interest cost	150	159
Actuarial (gain) loss	(143)	386
Curtailment gain	0	0
Benefits paid	(261)	(391)
Other	0	0
Benefit obligation at beginning of year	3,878	3,999	$ 3,721
Change in plan assets
Fair value of plan assets at beginning of year	3,217	3,236
Actual return on plan assets	27	240
Employer contributions	97	132
Benefits paid	(261)	(391)
Fair value of plan assets at end of year	3,080	3,217	3,236
Funded status at end of year	(798)	(782)
Amounts recognized in the consolidated balance sheets consist of1:
Current liabilities	(4)	(5)
Long-term liabilities	(794)	(777)
Total liabilities	(798)	(782)
Amounts recognized in accumulated other comprehensive loss consist of:
Net loss1	27	31
Amounts recognized in accumulated other comprehensive loss consist of:
Prior service cost	15	20
Net loss	660	640
Total amounts recognized as regulatory asset	675	660
Total not yet recognized as expense	702	691
Accumulated benefit obligation at end of year	3,744	3,881
Pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	3,878	3,999
Accumulated benefit obligation	3,744	3,881
Fair value of plan assets	$ 3,080	$ 3,217
Weighted-average assumptions used to determine obligations at end of year:
Discount rate	4.18%	3.85%
Rate of compensation increase	4.00%	4.00%
Defined Benefit Plan, Accumulated Other Comprehensive Income Net Gains (Losses), after Tax	$ 18	$ 22
Postretirement Benefits Other Than Pensions
Change in projected benefit obligation
Benefit obligation at beginning of year	2,784	2,220
Service cost	46	40	49
Interest cost	102	117	98
Special termination benefits	(2)	3
Actuarial (gain) loss	(500)	582
Plan participants' contributions	20	19
Benefits paid	(100)	(197)
Benefit obligation at beginning of year	2,350	2,784	2,220
Change in plan assets
Fair value of plan assets at beginning of year	2,086	2,065
Actual return on plan assets	6	180
Employer contributions	24	19
Plan participants' contributions	20	19
Benefits paid	(100)	(197)
Fair value of plan assets at end of year	2,036	2,086	2,065
Funded status at end of year	(314)	(698)
Amounts recognized in the consolidated balance sheets consist of1:
Current liabilities	(15)	(15)
Long-term liabilities	(299)	(683)
Total liabilities	(314)	(698)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax	4	4
Amounts recognized in accumulated other comprehensive loss consist of:
Prior service cost	(9)	(19)
Net loss	183	577
Total amounts recognized as regulatory asset	174	558
Total not yet recognized as expense	$ 178	$ 562
Weighted-average assumptions used to determine obligations at end of year:
Discount rate	4.55%	4.16%
Rate assumed for following year	7.50%	7.75%
Ultimate rate	5.00%	5.00%
Year ultimate rate reached	2022	2021
Postretirement Benefits Other Than Pensions | Southern California Edison
Change in projected benefit obligation
Benefit obligation at beginning of year	$ 2,775	$ 2,211
Service cost	46	40	48
Interest cost	102	117	97
Special termination benefits	(2)	3
Actuarial (gain) loss	(500)	582
Plan participants' contributions	20	19
Benefits paid	(100)	(197)
Benefit obligation at beginning of year	2,341	2,775	2,211
Change in plan assets
Fair value of plan assets at beginning of year	2,086	2,065
Actual return on plan assets	6	180
Employer contributions	24	19
Plan participants' contributions	20	19
Benefits paid	(100)	(197)
Fair value of plan assets at end of year	2,036	2,086	$ 2,065
Funded status at end of year	(305)	(689)
Amounts recognized in the consolidated balance sheets consist of1:
Current liabilities	(15)	(15)
Long-term liabilities	(290)	(674)
Total liabilities	(305)	(689)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax	0	0
Amounts recognized in accumulated other comprehensive loss consist of:
Prior service cost	(9)	(19)
Net loss	183	577
Total amounts recognized as regulatory asset	174	558
Total not yet recognized as expense	$ 174	$ 558
Weighted-average assumptions used to determine obligations at end of year:
Discount rate	4.55%	4.16%
Rate assumed for following year	7.50%	7.75%
Ultimate rate	5.00%	5.00%
Year ultimate rate reached	2022	2021
Edison International | Postretirement Benefits Other Than Pensions
Weighted-average assumptions used to determine obligations at end of year:
Long-term payable	$ 123	$ 121