Derivative Instruments (Details Textuals) (USD $)	3 Months Ended		9 Months Ended									9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Commodity contracts	Sep. 30, 2013 NUGs	Sep. 30, 2013 FTRs	Sep. 30, 2013 FES Commodity contracts	Sep. 30, 2013 FES FTRs	Sep. 30, 2013 JCP&L contracts	Oct. 11, 2013 JCP&L Subsequent Event appeal	Sep. 30, 2013 Cash Flow Hedges agreements	Dec. 31, 2012 Cash Flow Hedges agreements	Sep. 30, 2013 Fair Value Hedging agreements	Sep. 30, 2012 Fair Value Hedging	Sep. 30, 2013 Fair Value Hedging agreements	Sep. 30, 2012 Fair Value Hedging	Dec. 31, 2012 Fair Value Hedging agreements
Derivative [Line Items]
Unamortized gains or losses associated with designated cash flow hedges	$ 5,000,000		$ 5,000,000	$ 10,000,000
Gain (loss) on cash flow hedge expected to be reclassified to earnings in next twelve months			10,000,000
Number of forward starting swap agreements accounted for as a cash flow hedge outstanding												0	0
Unamortized gains or losses associated with prior interest rate hedges	61,000,000		61,000,000	70,000,000
Losses to be amortized to interest expenses during next twelve months												9,000,000				13,000,000
Number of fixed-for-floating interest rate swap agreements outstanding														0		0		0
Gains included in long-term debt associated with prior fixed-for-floating interest rate swap agreements	48,000,000		48,000,000	79,000,000
Reclassifications from long-term debt														4,000,000	6,000,000	15,000,000	17,000,000
Unamortized gain (loss) on extinguishment of debt	9,000,000		17,000,000											9,000,000		17,000,000
Net asset position under commodity derivative contracts					89,000,000
Collateral posted								43,000,000	6,000,000
Additional collateral related to commodity derivatives								9,000,000
Expected adverse change in quoted market prices of derivative instruments	10.00%		10.00%
Decrease net income due to adverse change in commodity prices			27,000,000
Proceeds from Interest Rate Derivative, Termination		6,000,000
Liability position						210,000,000	11,000,000
Number of outstanding LCAPP contracts										2
Number of appeals dismissed											2
Period in which LSEs may request direct allocation of FTRs			2 years
Direct allocation of FTRs, cost			$ 0