Income Taxes	9 Months Ended
Sep. 30, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES FirstEnergy’s and FES’ interim effective tax rates reflect the estimated annual effective tax rates for 2017 and 2016. These tax rates are affected by estimated annual permanent items, such as AFUDC equity and other flow-through items, as well as discrete items that may occur in any given period, but are not consistent from period to period. FirstEnergy’s effective tax rate for the three months ended September 30, 2017 and 2016 was 37.6% and 39.8%, respectively. FirstEnergy’s effective tax rate for the nine months ended September 30, 2017 was 38.3%. For the nine months ended September 30, 2017, the change in the effective tax rate, as compared to the same period for 2016, is primarily due to the impairment of $800 million of goodwill recognized in 2016, of which $433 million was non-deductible for tax purposes. Additionally, $159 million of valuation allowances were recorded in 2016 against state and municipal NOL carryforwards that also impacted the 2016 effective tax rate. FES’ effective tax rate for the three months ended September 30, 2017 and 2016 was 29.6% and 58.3%, respectively. FES' effective tax rate for the nine months ended September 30, 2017 and 2016 was 48.3% and 1.8%, respectively. For the nine months ended September 30, 2017, the change in the effective tax rate was primarily due to $65 million of valuation allowance recognized in 2016 against state and local NOL carryforwards and the impairment of goodwill also recognized in 2016, of which $23 million was non-deductible for tax purposes. As of September 30, 2017, it is reasonably possible that approximately $51 million of unrecognized tax benefits may be resolved within the next twelve months as a result of the statute of limitations expiring and expected resolution with respect to certain claims, of which approximately $26 million would affect FirstEnergy's effective tax rate. In August 2017 and February 2017, the IRS completed its examination of FirstEnergy's 2016 and 2015 federal income tax returns, respectively. The IRS has issued Full Acceptance Letters with no changes or adjustments to FirstEnergy's taxable income in either tax year.

INCOME TAXES

FirstEnergy’s and FES’ interim effective tax rates reflect the estimated annual effective tax rates for 2017 and 2016. These tax rates are affected by estimated annual permanent items, such as AFUDC equity and other flow-through items, as well as discrete items that may occur in any given period, but are not consistent from period to period.

FirstEnergy’s effective tax rate for the three months ended September 30, 2017 and 2016 was 37.6% and 39.8%, respectively. FirstEnergy’s effective tax rate for the nine months ended September 30, 2017 was 38.3%. For the nine months ended September 30, 2017, the change in the effective tax rate, as compared to the same period for 2016, is primarily due to the impairment of $800 million of goodwill recognized in 2016, of which $433 million was non-deductible for tax purposes. Additionally, $159 million of valuation allowances were recorded in 2016 against state and municipal NOL carryforwards that also impacted the 2016 effective tax rate.

FES’ effective tax rate for the three months ended September 30, 2017 and 2016 was 29.6% and 58.3%, respectively. FES' effective tax rate for the nine months ended September 30, 2017 and 2016 was 48.3% and 1.8%, respectively. For the nine months ended September 30, 2017, the change in the effective tax rate was primarily due to $65 million of valuation allowance recognized in 2016 against state and local NOL carryforwards and the impairment of goodwill also recognized in 2016, of which $23 million was non-deductible for tax purposes.

As of September 30, 2017, it is reasonably possible that approximately $51 million of unrecognized tax benefits may be resolved within the next twelve months as a result of the statute of limitations expiring and expected resolution with respect to certain claims, of which approximately $26 million would affect FirstEnergy's effective tax rate.

In August 2017 and February 2017, the IRS completed its examination of FirstEnergy's 2016 and 2015 federal income tax returns, respectively. The IRS has issued Full Acceptance Letters with no changes or adjustments to FirstEnergy's taxable income in either tax year.