Basis of Presentation	3 Months Ended
Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Note 1—Basis of Presentation The unaudited interim consolidated financial statements include the accounts of the Company, a Texas corporation and a financial holding company registered under the Bank Holding Company Act of 1956, as amended, or BHCA, and its wholly-owned subsidiaries: First Financial Bank, National Association, Abilene, Texas; First Technology Services, Inc.; First Financial Trust & Asset Management Company, National Association; First Financial Investments, Inc.; and First Financial Insurance Agency, Inc. Through our subsidiary bank, we conduct a full-service commercial banking business. Our banking centers are located primarily in Central, North Central, Southeast and West Texas. As of March 31, 2018, we had 72 financial centers across Texas, with eleven locations in Abilene, three locations in Weatherford, two locations in Cleburne, Conroe, San Angelo, Stephenville and Granbury, and one location each in Acton, Albany, Aledo, Alvarado, Beaumont, Boyd, Bridgeport, Brock, Burleson, Cisco, Clyde, Cut and Shoot, Decatur, Eastland, El Campo, Fort Worth, Fulshear, Glen Rose, Grapevine, Hereford, Huntsville, Keller, Kingwood, Magnolia, Mauriceville, Merkel, Midlothian, Mineral Wells, Montgomery, Moran, New Waverly, Newton, Odessa, Orange, Palacios, Port Arthur, Ranger, Rising Star, Roby, Southlake, Sweetwater, Tomball, Trent, Trophy Club, Vidor, Waxahachie, Willis and Willow Park, all in Texas. Our trust subsidiary has seven locations which are located in Abilene, Fort Worth, Odessa, Beaumont, San Angelo, Stephenville and Sweetwater. In the opinion of management, the unaudited interim consolidated financial statements reflect all adjustments necessary for a fair presentation of the Company’s financial position and unaudited results of operations and should be read in conjunction with the Company’s audited consolidated financial statements, and notes thereto in the Company’s Annual Report on Form 10-K, for the year ended December 31, 2017. All adjustments were of a normal recurring nature. However, the results of operations for the three months ended March 31, 2018, are not necessarily indicative of the results to be expected for the year ending December 31, 2018, due to seasonality, changes in economic conditions and loan credit quality, interest rate fluctuations, regulatory and legislative changes and other factors. The preparation of financial statements in conformity with United States generally accepted accounting principles (“GAAP”) require management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the financial statement date. Actual results could vary. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted under U.S. Securities and Exchange Commission (“SEC”) rules and regulations. The Company evaluated subsequent events for potential recognition and/or disclosure through the date the consolidated financial statements were issued. Goodwill and other intangible assets are evaluated annually for impairment as of the end of the second quarter. No such impairment has been noted in connection with the current or any prior evaluations. New Revenue Recognition Standard ASC 606, “Revenue from Contracts with Customers” established principles for reporting information about the nature, amount, timing and uncertainty of revenue and cash flows arising from the entity’s contracts to provide goods or services to customers. The core principle requires an entity to recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration that it expects to be entitled to receive in exchange for those goods or services recognized as performance obligations are satisfied. The majority of the Company’s revenue is derived from loan and investment income which are specifically excluded from the scope of this standard. Of the Company’s remaining sources of income, substantially all sources of revenue are recognized either by transaction (ATM, interchange, wire transfer, etc.) or when the Company charges a customer for a service that has already been rendered (monthly service charges, account fees, monthly trust management fees, etc.). Payment for such performance obligations are generally received at the time the performance obligations are satisfied. Other non-interest income primarily includes items such as letter of credit fees, gains on the sale of loans held for sale and servicing fees, none of which are subject to the requirements of ASC 606.

Note 1—Basis of Presentation

The unaudited interim consolidated financial statements include the accounts of the Company, a Texas corporation and a financial holding company registered under the Bank Holding Company Act of 1956, as amended, or BHCA, and its wholly-owned subsidiaries: First Financial Bank, National Association, Abilene, Texas; First Technology Services, Inc.; First Financial Trust & Asset Management Company, National Association; First Financial Investments, Inc.; and First Financial Insurance Agency, Inc.

Through our subsidiary bank, we conduct a full-service commercial banking business. Our banking centers are located primarily in Central, North Central, Southeast and West Texas. As of March 31, 2018, we had 72 financial centers across Texas, with eleven locations in Abilene, three locations in Weatherford, two locations in Cleburne, Conroe, San Angelo, Stephenville and Granbury, and one location each in Acton, Albany, Aledo, Alvarado, Beaumont, Boyd, Bridgeport, Brock, Burleson, Cisco, Clyde, Cut and Shoot, Decatur, Eastland, El Campo, Fort Worth, Fulshear, Glen Rose, Grapevine, Hereford, Huntsville, Keller, Kingwood, Magnolia, Mauriceville, Merkel, Midlothian, Mineral Wells, Montgomery, Moran, New Waverly, Newton, Odessa, Orange, Palacios, Port Arthur, Ranger, Rising Star, Roby, Southlake, Sweetwater, Tomball, Trent, Trophy Club, Vidor, Waxahachie, Willis and Willow Park, all in Texas. Our trust subsidiary has seven locations which are located in Abilene, Fort Worth, Odessa, Beaumont, San Angelo, Stephenville and Sweetwater.

In the opinion of management, the unaudited interim consolidated financial statements reflect all adjustments necessary for a fair presentation of the Company’s financial position and unaudited results of operations and should be read in conjunction with the Company’s audited consolidated financial statements, and notes thereto in the Company’s Annual Report on Form 10-K, for the year ended December 31, 2017. All adjustments were of a normal recurring nature. However, the results of operations for the three months ended March 31, 2018, are not necessarily indicative of the results to be expected for the year ending December 31, 2018, due to seasonality, changes in economic conditions and loan credit quality, interest rate fluctuations, regulatory and legislative changes and other factors. The preparation of financial statements in conformity with United States generally accepted accounting principles (“GAAP”) require management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the financial statement date. Actual results could vary. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted under U.S. Securities and Exchange Commission (“SEC”) rules and regulations. The Company evaluated subsequent events for potential recognition and/or disclosure through the date the consolidated financial statements were issued.

Goodwill and other intangible assets are evaluated annually for impairment as of the end of the second quarter. No such impairment has been noted in connection with the current or any prior evaluations.

New Revenue Recognition Standard

ASC 606, “Revenue from Contracts with Customers” established principles for reporting information about the nature, amount, timing and uncertainty of revenue and cash flows arising from the entity’s contracts to provide goods or services to customers. The core principle requires an entity to recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration that it expects to be entitled to receive in exchange for those goods or services recognized as performance obligations are satisfied.

The majority of the Company’s revenue is derived from loan and investment income which are specifically excluded from the scope of this standard. Of the Company’s remaining sources of income, substantially all sources of revenue are recognized either by transaction (ATM, interchange, wire transfer, etc.) or when the Company charges a customer for a service that has already been rendered (monthly service charges, account fees, monthly trust management fees, etc.). Payment for such performance obligations are generally received at the time the performance obligations are satisfied. Other non-interest income primarily includes items such as letter of credit fees, gains on the sale of loans held for sale and servicing fees, none of which are subject to the requirements of ASC 606.