Description of Business and Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim consolidated financial statements include the accounts of BancFirst Corporation, Council Oak Partners, LLC, BancFirst Insurance Services, Inc., Pegasus Bank ("Pegasus"), Worthington Bank ("Worthington") and BancFirst and its subsidiaries ("BancFirst"). The principal operating subsidiaries of BancFirst are BFTower, LLC, BFC-PNC LLC, and BancFirst Agency, Inc. All significant intercompany accounts and transactions have been eliminated. Assets held in a fiduciary or agency capacity are not assets of the Company and, accordingly, are not included in the unaudited interim consolidated financial statements. The accompanying unaudited interim consolidated financial statements and notes are presented in accordance with U.S. GAAP for interim financial information and the instructions for Form 10-Q adopted by the Securities and Exchange Commission (“SEC”). The information contained in the consolidated financial statements and footnotes included in BancFirst Corporation’s Annual Report on Form 10-K for the year ended December 31, 2023, should be referred to in connection with these unaudited interim consolidated financial statements. Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year or any future period. The unaudited interim consolidated financial statements contained herein reflect all adjustments, which are, in the opinion of management, necessary to provide a fair statement of the financial position and results of operations of the Company for the interim periods presented. All such adjustments are of a normal and recurring nature.
Reclassifications	Reclassifications Certain items in prior consolidated financial statements have been reclassified to conform to the current presentation. Such reclassifications had no effect on previously reported cash flows, stockholders’ equity or comprehensive income.
Use of Estimates in the Preparation of Financial Statements	Use of Estimates in the Preparation of Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the United States inherently involves the use of estimates and assumptions that affect the amounts reported in the financial statements and the related disclosures. These estimates relate principally to the determination of the allowance for credit losses, income taxes, the fair value of financial instruments and the valuation of assets and liabilities acquired in a business combination, including identifiable intangible assets. Such estimates and assumptions may change over time and actual amounts realized may differ from those reported.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Standards Not Yet Adopted: In December 2023, the Financial Accounting Standards Board (“FASB“) issued Accounting Standards Update (“ASU”) No. 2023-09, “Income Taxes - Improvements to Income Tax Disclosures” requiring enhancements and further transparency to certain income tax disclosures, most notably the tax rate reconciliation and income taxes paid. This ASU is effective for fiscal years beginning after December 15, 2024 on a prospective basis and retrospective application is permitted. The Company does not expect adoption of the standard to have a material impact on its consolidated financial statements. In November 2023, the FASB issued ASU 2023-07, “Segment Reporting - Improvements to Reportable Segment Disclosures” requiring disclosure of incremental segment information on an annual and interim basis for all public entities to enable investors to develop more decision-useful financial analyses. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 on a retrospective basis. The amendments are to be applied retrospectively to all periods presented and segment expense categories are required to be based on the categories identified at adoption. The Company is currently evaluating the provisions of this ASU and expects to adopt them for the year ending December 31, 2024. The Company does not expect the adoption to have a significant impact on the Company’s consolidated financial statements.

Description of Business and Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2024

The accompanying unaudited interim consolidated financial statements include the accounts of BancFirst Corporation, Council Oak Partners, LLC, BancFirst Insurance Services, Inc., Pegasus Bank ("Pegasus"), Worthington Bank ("Worthington") and BancFirst and its subsidiaries ("BancFirst"). The principal operating subsidiaries of BancFirst are BFTower, LLC, BFC-PNC LLC, and BancFirst Agency, Inc. All significant intercompany accounts and transactions have been eliminated. Assets held in a fiduciary or agency capacity are not assets of the Company and, accordingly, are not included in the unaudited interim consolidated financial statements.

The accompanying unaudited interim consolidated financial statements and notes are presented in accordance with U.S. GAAP for interim financial information and the instructions for Form 10-Q adopted by the Securities and Exchange Commission (“SEC”). The information contained in the consolidated financial statements and footnotes included in BancFirst Corporation’s Annual Report on Form 10-K for the year ended December 31, 2023, should be referred to in connection with these unaudited interim consolidated financial statements. Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year or any future period.

The unaudited interim consolidated financial statements contained herein reflect all adjustments, which are, in the opinion of management, necessary to provide a fair statement of the financial position and results of operations of the Company for the interim periods presented. All such adjustments are of a normal and recurring nature.

Reclassifications

Certain items in prior consolidated financial statements have been reclassified to conform to the current presentation. Such reclassifications had no effect on previously reported cash flows, stockholders’ equity or comprehensive income.

Use of Estimates in the Preparation of Financial Statements

The preparation of financial statements in conformity with accounting principles generally accepted in the United States inherently involves the use of estimates and assumptions that affect the amounts reported in the financial statements and the related disclosures. These estimates relate principally to the determination of the allowance for credit losses, income taxes, the fair value of financial instruments and the valuation of assets and liabilities acquired in a business combination, including identifiable intangible assets. Such estimates and assumptions may change over time and actual amounts realized may differ from those reported.

Recent Accounting Pronouncements

Standards Not Yet Adopted:

In December 2023, the Financial Accounting Standards Board (“FASB“) issued Accounting Standards Update (“ASU”) No. 2023-09, “Income Taxes - Improvements to Income Tax Disclosures” requiring enhancements and further transparency to certain income tax disclosures, most notably the tax rate reconciliation and income taxes paid. This ASU is effective for fiscal years beginning after December 15, 2024 on a prospective basis and retrospective application is permitted. The Company does not expect adoption of the standard to have a material impact on its consolidated financial statements.

In November 2023, the FASB issued ASU 2023-07, “Segment Reporting - Improvements to Reportable Segment Disclosures” requiring disclosure of incremental segment information on an annual and interim basis for all public entities to enable investors to develop more decision-useful financial analyses. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 on a retrospective basis. The amendments are to be applied retrospectively to all periods presented and segment expense categories are required to be based on the categories identified at adoption. The Company is currently evaluating the provisions of this ASU and expects to adopt them for the year ending December 31, 2024. The Company does not expect the adoption to have a significant impact on the Company’s consolidated financial statements.