Compensation and Benefit Plans (Expense Components) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 12	$ 11	$ 24	$ 22
Interest cost	28	27	57	54
Expected return on plan assets	(29)	(28)	(57)	(56)
Amortization of prior service cost	(3)	(9)	(6)	(18)
Amortization of net loss	6	0	12	0
Expense under accounting standards	14	1	30	2
Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	35	29	70	59
Interest cost	42	48	83	93
Expected return on plan assets	(57)	(60)	(114)	(117)
Amortization of prior service cost	1	2	2	3
Amortization of net loss	9	1	18	2
Expense under accounting standards	30	20	59	40
Regulatory adjustment	(2)	30	(3)	61
Total expense recognized	28	50	56	101
Net loss reclassified	4	1	7	3
Southern California Edison
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	12	11	24	22
Interest cost	28	27	56	54
Expected return on plan assets	(28)	(28)	(56)	(56)
Amortization of prior service cost	(3)	(9)	(6)	(18)
Amortization of net loss	5	0	11	0
Expense under accounting standards	14	1	29	2
Southern California Edison | Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	34	29	69	58
Interest cost	37	44	75	88
Expected return on plan assets	(54)	(56)	(107)	(112)
Amortization of prior service cost	2	1	3	2
Amortization of net loss	8	1	15	1
Expense under accounting standards	27	19	55	37
Regulatory adjustment	(1)	30	(2)	61
Total expense recognized	26	49	53	98
Net loss reclassified	$ 2	$ 1	$ 4	$ 2