Income Taxes (Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Line Items]
Income from continuing operations before income taxes	$ 571		$ 487	$ 1,162	$ 1,324
Provision for income tax at federal statutory rate of 35%	200		170	407	463
Increase in income tax from:
State tax, net of federal benefit	20		6	30	23
Property-related	(79)		(79)	(296)	(207)
Change related to uncertain tax positions	(5)		10	(4)	(53)
Other	(14)		(25)	(24)	(31)
Total income tax (benefit) expense from continuing operations	$ 122		$ 82	$ 113	$ 195
Effective tax rate	21.40%		16.80%	9.70%	14.70%
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	$ 607		$ 509	$ 1,291	$ 1,370
Provision for income tax at federal statutory rate of 35%	212		178	452	480
Increase in income tax from:
State tax, net of federal benefit	25		8	40	23
Property-related	(79)		(79)	(296)	(207)
Change related to uncertain tax positions	(7)		9	(9)	(56)
Other	(10)		(24)	(25)	(33)
Total income tax (benefit) expense from continuing operations	$ 141		$ 92	$ 162	$ 207
Effective tax rate	23.20%		18.10%	12.50%	15.10%
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:
Incremental tax benefits related to repair deductions		$ 79
Incremental tax benefits related to repair deductions, pre tax		$ 133