Compensation and Benefit Plans (Expense Components) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 31	$ 32	$ 62	$ 64
Non-service cost (benefit)
Interest cost	30	39	61	78
Expected return on plan assets	(54)	(52)	(108)	(104)
Amortization of prior service cost	1	1	1	1
Amortization of net (loss) gain	3	2	6	4
Regulatory adjustment	2	(4)	4	(8)
Total non-service cost (benefit)	(18)	(14)	(36)	(29)
Total expense recognized	13	18	26	35
PBOP Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	8	18	16
Non-service cost (benefit)
Interest cost	17	21	34	42
Expected return on plan assets	(30)	(28)	(60)	(56)
Amortization of net (loss) gain	(4)	(1)	(8)	(2)
Regulatory adjustment	8	6	16	12
Total non-service cost (benefit)	(9)	(2)	(18)	(4)
Total expense	0	6	0	12
Southern California Edison
Non-service cost (benefit)
Total non-service cost (benefit)	(27)	(16)	(55)	(35)
Southern California Edison | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	30	31	60	62
Non-service cost (benefit)
Interest cost	28	36	56	71
Expected return on plan assets	(51)	(49)	(102)	(98)
Amortization of prior service cost	1	1	1	1
Amortization of net (loss) gain	2	2	4	3
Regulatory adjustment	2	(4)	4	(8)
Total non-service cost (benefit)	(18)	(14)	(37)	(31)
Total expense recognized	12	17	23	31
Southern California Edison | PBOP Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	8	18	16
Non-service cost (benefit)
Interest cost	17	21	34	42
Expected return on plan assets	(30)	(28)	(60)	(56)
Amortization of net (loss) gain	(4)	(1)	(8)	(2)
Regulatory adjustment	8	6	16	12
Total non-service cost (benefit)	(9)	(2)	(18)	(4)
Total expense	$ 0	$ 6	$ 0	$ 12