Income Taxes (Textual) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Apr. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Line Items]
Less valuation allowance				$ 24
Valuation allowance for assets				8
Unrecognized tax benefits that would impact the effective tax rate			$ 440	347	$ 440
IRS Examination | Tax Years 2010 to 2012
Income Tax Disclosure [Line Items]
Federal tax liability					(94)
Disallowance of Repair Allowance Deduction
Income Tax Disclosure [Line Items]
Federal tax liability						$ (133)
Base rate offset			324		$ 324
Rate base offset amortization period (years)					27 years
Capistrano Wind | Affiliated Entity | Tax Allocation Agreement
Income Tax Disclosure [Line Items]
Due to affiliate under tax allocation agreements			210	242	$ 210
SCE
Income Tax Disclosure [Line Items]
Granted BRRBA reduction	$ 234
Refund		$ 133
After tax refund		$ 79
Unrecognized tax benefits that would impact the effective tax rate			256	$ 243	256
SCE | IRS Examination | Tax Years 2010 to 2012
Income Tax Disclosure [Line Items]
Federal tax liability					(100)
SCE | Disallowance of Repair Allowance Deduction
Income Tax Disclosure [Line Items]
Federal tax liability			382		382
Retained Earnings | Accounting standards update to simplify the accounting for share-based payments | Early adoption using modified retrospective approach
Income Tax Disclosure [Line Items]
Cumulative effect adjustment			42		42
Retained Earnings | Accounting standards update to simplify the accounting for share-based payments | Early adoption using modified retrospective approach | SCE
Income Tax Disclosure [Line Items]
Cumulative effect adjustment			$ 6		$ 6