Income Taxes	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes At March 31, 2018 and December 31, 2017, First Commonwealth had no material unrecognized tax benefits or accrued interest and penalties. If applicable, First Commonwealth will record interest and penalties as a component of noninterest expense. Federal and state returns for tax years 2014 and forward remain open for examination as of March 31, 2018. During the first quarter of 2018, First Commonwealth adopted ASU No. 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220)". Adoption of this ASU reclassified the stranded other accumulated income of $1.3 million resulting from the tax reform passed in December 2017 from accumulated other comprehensive income to retained earnings. There was no impact to total equity as a result of the adoption of this update. During the first quarter of 2017, First Commonwealth adopted ASU No. 2016-09, "Compensation-Stock Compensation (Topic 718)." Adoption of this ASU resulted in a $0.1 million tax benefit.

Income Taxes

3 Months Ended

Mar. 31, 2018

At March 31, 2018 and December 31, 2017, First Commonwealth had no material unrecognized tax benefits or accrued interest and penalties. If applicable, First Commonwealth will record interest and penalties as a component of noninterest expense. Federal and state returns for tax years 2014 and forward remain open for examination as of March 31, 2018.

During the first quarter of 2018, First Commonwealth adopted ASU No. 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220)". Adoption of this ASU reclassified the stranded other accumulated income of $1.3 million resulting from the tax reform passed in December 2017 from accumulated other comprehensive income to retained earnings. There was no impact to total equity as a result of the adoption of this update. During the first quarter of 2017, First Commonwealth adopted ASU No. 2016-09, "Compensation-Stock Compensation (Topic 718)." Adoption of this ASU resulted in a $0.1 million tax benefit.