Description of Business and Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2022
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 National Bank ("Worthington") and BancFirst and its subsidiaries. The principal operating subsidiaries of BancFirst are Council Oak Investment Corporation, Council Oak Real Estate, Inc., 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, 2021, 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 intangibles. 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 March 2022, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2022-02, “Financial Instruments – Credit Losses (Topic 326).” ASU 2022-02 eliminates the TDR recognition and measurement guidance and, instead, requires that the Company evaluate, based on the accounting for loan modifications, whether the modification represents a new loan or a continuation of an existing loan. The Company has the option to apply a modified retrospective transition method, resulting in a cumulative-effect adjustment to retained earnings when adopted. In addition, the update requires that the Company disclose current-period write-offs by year of origination for financing receivables. The current-period write-off amendment should be applied prospectively. The amendments are effective for annual periods beginning after December 15, 2022, including interim periods within those annual periods. Early adoption is permitted; however the Company expects to adopt ASU 2022-02 on January 1, 2023. ASU No. 2022-02 is not expected to have a significant impact on the Company’s consolidated financial statements.

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

6 Months Ended

Jun. 30, 2022

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 National Bank ("Worthington") and BancFirst and its subsidiaries. The principal operating subsidiaries of BancFirst are Council Oak Investment Corporation, Council Oak Real Estate, Inc., 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, 2021, 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 intangibles. 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 March 2022, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2022-02, “Financial Instruments – Credit Losses (Topic 326).” ASU 2022-02 eliminates the TDR recognition and measurement guidance and, instead, requires that the Company evaluate, based on the accounting for loan modifications, whether the modification represents a new loan or a continuation of an existing loan. The Company has the option to apply a modified retrospective transition method, resulting in a cumulative-effect adjustment to retained earnings when adopted. In addition, the update requires that the Company disclose current-period write-offs by year of origination for financing receivables. The current-period write-off amendment should be applied prospectively. The amendments are effective for annual periods beginning after December 15, 2022, including interim periods within those annual periods. Early adoption is permitted; however the Company expects to adopt ASU 2022-02 on January 1, 2023. ASU No. 2022-02 is not expected to have a significant impact on the Company’s consolidated financial statements.