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Fair Value Measurements (Details Textuals) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2014
Dec. 31, 2013
Fair Value of Financial Instruments [Line Items]      
Investment excludes Receivables, Payables and Accrued income   40fe_InvestmentsExcludesReceivablesPayablesDeferredTaxesAndAccruedIncome $ 10fe_InvestmentsExcludesReceivablesPayablesDeferredTaxesAndAccruedIncome
Cash balance excluded from available for sale securities   241fe_CashReceivablesPayablesDeferredTaxesAccruedIncomeBalanceExcludedFromAvailableForSaleSecurities 204fe_CashReceivablesPayablesDeferredTaxesAccruedIncomeBalanceExcludedFromAvailableForSaleSecurities
Investments not required to be disclosed   626fe_InvestmentsNotRequiredToBeDisclosed 636fe_InvestmentsNotRequiredToBeDisclosed
Equity Method Investment, Adjustment 9fe_EquityMethodInvestmentAdjustment    
FES      
Fair Value of Financial Instruments [Line Items]      
Investment excludes Receivables, Payables and Accrued income   44fe_InvestmentsExcludesReceivablesPayablesDeferredTaxesAndAccruedIncome
/ dei_LegalEntityAxis
= fe_FesMember		 9fe_InvestmentsExcludesReceivablesPayablesDeferredTaxesAndAccruedIncome
/ dei_LegalEntityAxis
= fe_FesMember
Cash balance excluded from available for sale securities   204fe_CashReceivablesPayablesDeferredTaxesAccruedIncomeBalanceExcludedFromAvailableForSaleSecurities
/ dei_LegalEntityAxis
= fe_FesMember		 $ 135fe_CashReceivablesPayablesDeferredTaxesAccruedIncomeBalanceExcludedFromAvailableForSaleSecurities
/ dei_LegalEntityAxis
= fe_FesMember
NUG contracts      
Fair Value of Financial Instruments [Line Items]      
Period of future observable data to determine contract price   3 years