XML 49 R34.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Asset Retirement Obligations (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2016
Asset Retirement Obligation [Abstract] |
Fair Values of the Decommissioning Trust Assets | FirstEnergy and FES maintain NDTs that are legally restricted for purposes of settling the nuclear decommissioning ARO. The fair values of the decommissioning trust assets as of September 30, 2016 and December 31, 2015 were as follows:
|  | 2016 |  | 2015
|  | (In millions)
FirstEnergy |  | $ | 2,502 |  |  | $ | 2,282 |
FES |  | $ | 1,542 |  |  | $ | 1,327 |
Changes to ARO Balances | The following table summarizes the changes to the ARO balances during 2016:
ARO Reconciliation |  | FirstEnergy |  | FES
|  | (In millions)
Balance, December 31, 2015 |  | $ | 1,410 |  |  | $ | 831 |
Liabilities settled |  | (25 | ) |  | (17 | )
Liabilities incurred |  | 4 |  |  | 32 |
Accretion |  | 70 |  |  | 41 |
Balance, September 30, 2016 |  | $ | 1,459 |  |  | $ | 887 |

X
- Definition Asset Retirement Obligation Period Increase Decrease. + References No definition available. + Details
Name: | fe_AssetRetirementObligationPeriodIncreaseDecreaseTableTextBlock
Namespace Prefix: | fe_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair values of the decommissioning trust assets. + References No definition available. + Details
Name: | fe_FairValuesoftheDecommissioningTrustAssetsTableTextBlock
Namespace Prefix: | fe_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AssetRetirementObligationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration