Income Taxes (Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Tax Disclosure [Line Items]
Income from continuing operations before income taxes	$ 259	$ 412	$ 591	$ 837
Provision for income tax at federal statutory rate of 35%	91	144	207	293
Increase in income tax from:
State tax, net of federal benefit	4	5	11	16
Property-related	(138)	(69)	(217)	(129)
Change related to uncertain tax positions	2	(77)	1	(62)
Other	(6)	3	(11)	(5)
Total income tax (benefit) expense from continuing operations	$ (47)	$ 6	$ (9)	$ 113
Effective tax rate	(18.10%)	1.50%	(1.50%)	13.50%
Federal statutory rate	35.00%	35.00%	35.00%	35.00%
Southern California Edison
Income Tax Disclosure [Line Items]
Income from continuing operations before income taxes	$ 317	$ 419	$ 683	$ 860
Provision for income tax at federal statutory rate of 35%	111	147	239	301
Increase in income tax from:
State tax, net of federal benefit	6	2	15	16
Property-related	(138)	(69)	(217)	(129)
Change related to uncertain tax positions	(1)	(75)	(2)	(65)
Other	(7)	2	(14)	(8)
Total income tax (benefit) expense from continuing operations	$ (29)	$ 7	$ 21	$ 115
Effective tax rate	(9.10%)	1.70%	3.10%	13.40%
Federal statutory rate	35.00%	35.00%	35.00%	35.00%
Tax Years 2012 to 2014 | Internal Revenue Service (IRS) | Southern California Edison
Increase in income tax from:
Tax liability	$ 79
Tax adjustments, pre tax	$ 133