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Derivative Instruments (Details Textuals) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2017 USD ($) agreement | Jun. 30, 2016 USD ($) | Jun. 30, 2017 USD ($) agreement | Jun. 30, 2016 USD ($) | Dec. 31, 2016 USD ($) agreement
Derivative [Line Items] |  |  |  |  |
Unamortized gains (losses) associated with designated cash flow hedges | $ 12 |  | $ 12 |  | $ 12
Possible adverse change in quoted market prices of derivative instruments | 10.00% |  | 10.00% |  |
Possible increase (decrease) net income due to ten percent adverse change in commodity prices |  |  | $ (15) |  |
Cash Flow Hedges |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Cash flow hedge expected to be reclassified to earnings in next twelve months |  |  | 2 |  |
Unamortized gains or losses associated with prior interest rate hedges | $ 29 |  | 29 |  | $ 33
Gains (losses) to be amortized to interest expenses during next twelve months |  |  | $ (8) |  |
Number of outstanding commodity or interest rate derivatives | agreement | 0 |  | 0 |  | 0
Cash Flow Hedges | FES |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Unamortized gains or losses associated with prior interest rate hedges | $ 3 |  | $ 3 |  | $ 3
Fair Value Hedging |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Gains (losses) to be amortized to interest expenses during next twelve months |  |  | 3 |  |
Reclassifications from long-term debt | $ 2 | $ 3 | $ 4 | $ 6 |
Number of fixed-for-floating interest rate swap agreements outstanding | agreement | 0 |  | 0 |  | 0
Gains included in long-term debt associated with prior fixed-for-floating interest rate swap agreements | $ 6 |  | $ 6 |  | $ 10
Commodity contracts |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Net asset (liability) position | 32 |  | 32 |  |
Commodity contracts | FES |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Collateral posted | 1 |  | 1 |  |
NUGs |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Liability position | 99 |  | 99 |  |
FTRs |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Net asset (liability) position | 2 |  | 2 |  | 1
FTRs | FES |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Net asset (liability) position | $ (1) |  | $ (1) |  | $ (1)

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- Definition Gains (Losses) To Be Amortized To Interest Expenses During Next Twelve Months. + References No definition available. + Details
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- Definition Unamortized gains included in long-term debt associated with prior fixed-for-floating interest rate swap agreements. + References No definition available. + Details
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