Income Taxes (Operating Loss and Tax Carryforward) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Tax Credit Carryforward [Line Items]
Loss Carryforwards, Expiring 2015 to 2019	$ 3
Loss Carryforwards, Expiring 2020 to 2033	1,213
Loss Carryforwards, No expiration date	0
Loss Carryforwards	1,216
Credit Carryforward, Expiring 2015 to 2019	0
Credit Carryforward, Expiring 2020 to 2033	405
Credit Carryforward, No expiration date	36
Credit Carryforwards	441
Southern California Edison
Tax Credit Carryforward [Line Items]
Loss Carryforwards, Expiring 2015 to 2019	14
Loss Carryforwards, Expiring 2020 to 2033	132
Loss Carryforwards	146
Credit Carryforward, Expiring 2015 to 2019	0
Credit Carryforward, Expiring 2020 to 2033	39
Credit Carryforward, No expiration date	20
Credit Carryforwards	$ 59