New Accounting Pronouncements (Notes)	3 Months Ended
Mar. 31, 2019
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments,” which amends the guidance for recognizing credit losses from an “incurred loss” methodology that delays recognition of credit losses until it is probable a loss has been incurred to an expected credit loss methodology. The Current Expected Credit Loss ("CECL") methodology requires the use of the modified retrospective transition method by means of a cumulative-effect adjustment to equity as of the beginning of the period in which the guidance is adopted. The standard is effective for the Company as of January 1, 2020. We have established a CECL implementation team, which includes members from the finance and credit areas, with oversight by the Chief Executive Officer, Chief Financial Officer and Chief Credit Officer. During the third quarter of 2018, Management completed the implementation of third party software to assist with this ASU. In the fourth quarter of 2018, a third party was engaged to assist with evaluation of data and methodologies related to this standard. Management continued its implementation plan during the first quarter of 2019 with primary emphasis on the evaluation of data and methodologies. Management is currently evaluating the impact of the amended guidance on First Commonwealth’s financial condition or results of operations. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles-Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment" which simplifies the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. Under this ASU, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. Impairment should be recognized for the amount by which the carrying amount exceeds the reporting unit's fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to the reporting unit. Income tax effects from any tax deductible goodwill should be taken into consideration of the carrying amount of the reporting unit when measuring for goodwill impairment, if applicable. An entity still has the option to perform the qualitative assessment for the reporting unit to determine if the quantitative impairment test is necessary. This standard is effective for interim and annual periods for fiscal years beginning after December 15, 2019. The adoption of this ASU is not expected to have a material impact on First Commonwealth’s financial condition or results of operations. In August 2018, the FASB issued ASU No. 2018-13, "Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement." This ASU updates disclosure requirements for fair value measurements, including elimination of the disclosure related to the amount and reason for transfers between Level 1 and Level 2 of the fair value hierarchy. ASU No. 2018-13 is effective for interim and annual reporting periods beginning after December 15, 2019. Adoption of this ASU will not have a material impact on First Commonwealth's financial condition or results of operations, as it relates only to disclosure requirements.

New Accounting Pronouncements

In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments,” which amends the guidance for recognizing credit losses from an “incurred loss” methodology that delays recognition of credit losses until it is probable a loss has been incurred to an expected credit loss methodology. The Current Expected Credit Loss ("CECL") methodology requires the use of the modified retrospective transition method by means of a cumulative-effect adjustment to equity as of the beginning of the period in which the guidance is adopted. The standard is effective for the Company as of January 1, 2020. We have established a CECL implementation team, which includes members from the finance and credit areas, with oversight by the Chief Executive Officer, Chief Financial Officer and Chief Credit Officer. During the third quarter of 2018, Management completed the implementation of third party software to assist with this ASU. In the fourth quarter of 2018, a third party was engaged to assist with evaluation of data and methodologies related to this standard. Management continued its implementation plan during the first quarter of 2019 with primary emphasis on the evaluation of data and methodologies. Management is currently evaluating the impact of the amended guidance on First Commonwealth’s financial condition or results of operations.

In January 2017, the FASB issued ASU No. 2017-04, "Intangibles-Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment" which simplifies the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. Under this ASU, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. Impairment should be recognized for the amount by which the carrying amount exceeds the reporting unit's fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to the reporting unit. Income tax effects from any tax deductible goodwill should be taken into consideration of the carrying amount of the reporting unit when measuring for goodwill impairment, if applicable. An entity still has the option to perform the qualitative assessment for the reporting unit to determine if the quantitative impairment test is necessary. This standard is effective for interim and annual periods for fiscal years beginning after December 15, 2019. The adoption of this ASU is not expected to have a material impact on First Commonwealth’s financial condition or results of operations.

In August 2018, the FASB issued ASU No. 2018-13, "Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement." This ASU updates disclosure requirements for fair value measurements, including elimination of the disclosure related to the amount and reason for transfers between Level 1 and Level 2 of the fair value hierarchy. ASU No. 2018-13 is effective for interim and annual reporting periods beginning after December 15, 2019. Adoption of this ASU will not have a material impact on First Commonwealth's financial condition or results of operations, as it relates only to disclosure requirements.