Income Taxes (Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosures [Line Items]
Income from continuing operations before income taxes	$ 627	$ 432		$ 1,127	$ 1,119
Provision for income tax at federal statutory rate of 21% and 35%, respectively	132	151		237	392
Increase in income tax from:
State tax, net of federal benefit	26	7		21	23
Property-related	(76)	(201)		(214)	(396)
Change related to uncertain tax positions	1	0		1	(17)
Shared-based compensation	(1)	(4)		(1)	(50)
Other	1	(22)		(1)	(35)
Total income tax expense (benefit) from continuing operations	$ 83	$ (69)		$ 43	$ (83)
Effective tax rate	13.20%	(16.00%)		3.80%	(7.40%)
State
Increase in income tax from:
Shared-based compensation					$ 10
Southern California Edison
Income Tax Disclosures [Line Items]
Income from continuing operations before income taxes	$ 653	$ 462		$ 1,288	1,249
Provision for income tax at federal statutory rate of 21% and 35%, respectively	137	162		270	437
Increase in income tax from:
State tax, net of federal benefit	29	12		33	34
Property-related	(76)	(201)		(214)	(396)
Change related to uncertain tax positions	(1)	(1)		(2)	(13)
Shared-based compensation	(1)	(1)		(1)	(10)
Other	(2)	(6)		(8)	(18)
Total income tax expense (benefit) from continuing operations	$ 86	$ (35)		$ 78	$ 34
Effective tax rate	13.20%	(7.60%)		6.10%	2.70%
Tax abandonment loss			$ 39
Southern California Edison | Federal
Increase in income tax from:
Tax abandonment loss			691
Southern California Edison | Federal | Tax accounting method changes
Increase in income tax from:
Incremental tax benefits related to repair deductions		$ 70
Incremental tax benefits related to repair deductions, before tax		$ 118
Southern California Edison | State
Increase in income tax from:
Shared-based compensation					$ 2
Tax abandonment loss			$ 1,130