New Accounting Pronouncements (Notes)	9 Months Ended
Sep. 30, 2015
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements In January 2015, the FASB issued ASU No. 2015-01, "Income Statement - Extraordinary and Unusual Items (Subtopic 225-20)," which finalizes Proposed ASU No. 2014-220, and eliminates the concept of extraordinary items from U.S. GAAP. Accordingly, this ASU eliminates FASB ASC Subtopic 225-20, "Income Statement - Extraordinary and Unusual Items", which, until now, required that an entity separately classify, present, and disclose extraordinary events and transactions. This ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. The adoption of this ASU is not expected to have a material impact on First Commonwealth’s financial condition or results of operations. In September 2015, the FASB issued ASU No. 2015-16, "Business Combinations (Topic 805)," requires that the acquirer recognize adjustments to provisional amounts identified during the measurement period in the reporting period in which the adjustment amounts are determined. The adjustments are required to be presented separately on the face of the income statement or disclosed in the notes to show the portion of current-period earnings by line item that would have been recorded in previous reporting periods if the adjustments to the provisional amounts had been recognized as of the acquisition date. This ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. The adoption of this ASU is not expected to have a material impact on First Commonwealth’s financial condition or results of operations.

New Accounting Pronouncements

In January 2015, the FASB issued ASU No. 2015-01, "Income Statement - Extraordinary and Unusual Items (Subtopic 225-20)," which finalizes Proposed ASU No. 2014-220, and eliminates the concept of extraordinary items from U.S. GAAP. Accordingly, this ASU eliminates FASB ASC Subtopic 225-20, "Income Statement - Extraordinary and Unusual Items", which, until now, required that an entity separately classify, present, and disclose extraordinary events and transactions. This ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. The adoption of this ASU is not expected to have a material impact on First Commonwealth’s financial condition or results of operations.

In September 2015, the FASB issued ASU No. 2015-16, "Business Combinations (Topic 805)," requires that the acquirer recognize adjustments to provisional amounts identified during the measurement period in the reporting period in which the adjustment amounts are determined. The adjustments are required to be presented separately on the face of the income statement or disclosed in the notes to show the portion of current-period earnings by line item that would have been recorded in previous reporting periods if the adjustments to the provisional amounts had been recognized as of the acquisition date. This ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. The adoption of this ASU is not expected to have a material impact on First Commonwealth’s financial condition or results of operations.