Recent Developments, Including Mergers and Acquisitions	12 Months Ended
Dec. 31, 2018
Recent Developments Including Mergers And Acquisitions [Abstract]
Recent Developments, Including Mergers and Acquisitions	(2) RECENT DEVELOPMENTS, INCLUDING MERGERS AND ACQUISITIONS On August 31, 2018 BFTower, LLC, a wholly-owned subsidiary of BancFirst purchased Cotter Ranch Tower in Oklahoma City for the Company’s corporate headquarters for $21.0 million. Cotter Ranch Tower was subsequently renamed BancFirst Tower. BancFirst Tower consists of an aggregate of 507,000 square feet, has 36 floors and is the second tallest building in Oklahoma City. The tower will remain an income producing property as approximately 55% is currently leased to outside tenants. BancFirst Tower will allow the Company to consolidate operations from three locations to one and will improve operational efficiencies. Upon consolidation, the Company expects to occupy approximately 35% of the Tower, resulting in approximately 90% total occupancy. Renovations on BancFirst Tower will be completed over the next two years and are expected to cost approximately $60 million. The renovation costs include substantial deferred maintenance including HVAC, plumbing, electrical, elevators, building skin and roof while also including much needed improvements to both the interior and exterior common areas including the lobby, underground and outdoor plaza. The total purchase price and renovation costs were determined to be favorable to other alternatives, such as constructing new corporate headquarters. On December 14, 2018, BFTower LLC, purchased a 42.6% ownership interest in SFPG, LLC, which is the owner of a 1,568 space parking garage adjacent to BancFirst Tower, for $9.8 million. On January 11, 2018, the Company acquired First Wagoner Corp. and its subsidiary bank, First Bank & Trust Company, with locations in Carney, Grove, Ketchum, Luther, Tulsa and Wagoner. First Bank & Trust Company had approximately $290 million in total assets, $247 million in loans and $251 million in deposits. First Bank & Trust Company operated as a subsidiary of BancFirst Corporation until it was merged into BancFirst on February 16, 2018. As a result of the acquisition, the Company recorded a core deposit intangible of approximately $6.3 million and goodwill of approximately $19.1 million. The effect of this acquisition was included in the consolidated financial statements of the Company from the date of acquisition forward. The acquisition did not have a material effect on the Company’s consolidated financial statements. The acquisition of First Wagoner Corp. and its subsidiary bank, First Bank & Trust Company complements the Company’s community banking strategy by adding an additional five communities to its banking network in Oklahoma. On January 11, 2018, the Company acquired First Chandler Corp. and its subsidiary bank, First Bank of Chandler, with two locations in Chandler. First Bank of Chandler had approximately $88 million in total assets, $66 million in loans and $79 million in deposits. First Bank of Chandler operated as a subsidiary of BancFirst Corporation until it was merged into BancFirst on September 7, 2018. As a result of the acquisition, the Company recorded a core deposit intangible of approximately $2.2 million and goodwill of approximately $6.6 million. The effect of this acquisition was included in the consolidated financial statements of the Company from the date of acquisition forward. The acquisition did not have a material effect on the Company’s consolidated financial statements. The acquisition of First Chandler Corp. and its subsidiary bank, First Bank of Chandler complements the Company’s community banking strategy by increasing its banking network in Oklahoma. On July 31, 2017, the Company completed a two-for-one stock split of the Company’s outstanding shares of common stock. The stock was payable in the form of a dividend on or about July 31, 2017 to shareholders of record of the outstanding common stock as of the close of business record date of July 17, 2017. Stockholders received one additional share for each share held on that date. This was the second stock split for the Company since going public. All share and per share amounts in these consolidated financial statements and related notes have been retroactively adjusted to reflect this stock split for all periods presented. Effective June 1, 2017, the Company organized a new wholly-owned captive insurance company named BancFirst Risk & Insurance Company. It insures certain risks of the Company and has entered into reinsurance agreements with a risk-sharing pool.

Recent Developments, Including Mergers and Acquisitions

12 Months Ended

Dec. 31, 2018

Recent Developments Including Mergers And Acquisitions [Abstract]

Recent Developments, Including Mergers and Acquisitions

(2) RECENT DEVELOPMENTS, INCLUDING MERGERS AND ACQUISITIONS

On August 31, 2018 BFTower, LLC, a wholly-owned subsidiary of BancFirst purchased Cotter Ranch Tower in Oklahoma City for the Company’s corporate headquarters for $21.0 million. Cotter Ranch Tower was subsequently renamed BancFirst Tower. BancFirst Tower consists of an aggregate of 507,000 square feet, has 36 floors and is the second tallest building in Oklahoma City. The tower will remain an income producing property as approximately 55% is currently leased to outside tenants. BancFirst Tower will allow the Company to consolidate operations from three locations to one and will improve operational efficiencies. Upon consolidation, the Company expects to occupy approximately 35% of the Tower, resulting in approximately 90% total occupancy. Renovations on BancFirst Tower will be completed over the next two years and are expected to cost approximately $60 million. The renovation costs include substantial deferred maintenance including HVAC, plumbing, electrical, elevators, building skin and roof while also including much needed improvements to both the interior and exterior common areas including the lobby, underground and outdoor plaza. The total purchase price and renovation costs were determined to be favorable to other alternatives, such as constructing new corporate headquarters. On December 14, 2018, BFTower LLC, purchased a 42.6% ownership interest in SFPG, LLC, which is the owner of a 1,568 space parking garage adjacent to BancFirst Tower, for $9.8 million.

On January 11, 2018, the Company acquired First Wagoner Corp. and its subsidiary bank, First Bank & Trust Company, with locations in Carney, Grove, Ketchum, Luther, Tulsa and Wagoner. First Bank & Trust Company had approximately $290 million in total assets, $247 million in loans and $251 million in deposits. First Bank & Trust Company operated as a subsidiary of BancFirst Corporation until it was merged into BancFirst on February 16, 2018. As a result of the acquisition, the Company recorded a core deposit intangible of approximately $6.3 million and goodwill of approximately $19.1 million. The effect of this acquisition was included in the consolidated financial statements of the Company from the date of acquisition forward. The acquisition did not have a material effect on the Company’s consolidated financial statements. The acquisition of First Wagoner Corp. and its subsidiary bank, First Bank & Trust Company complements the Company’s community banking strategy by adding an additional five communities to its banking network in Oklahoma.

On January 11, 2018, the Company acquired First Chandler Corp. and its subsidiary bank, First Bank of Chandler, with two locations in Chandler. First Bank of Chandler had approximately $88 million in total assets, $66 million in loans and $79 million in deposits. First Bank of Chandler operated as a subsidiary of BancFirst Corporation until it was merged into BancFirst on September 7, 2018. As a result of the acquisition, the Company recorded a core deposit intangible of approximately $2.2 million and goodwill of approximately $6.6 million. The effect of this acquisition was included in the consolidated financial statements of the Company from the date of acquisition forward. The acquisition did not have a material effect on the Company’s consolidated financial statements. The acquisition of First Chandler Corp. and its subsidiary bank, First Bank of Chandler complements the Company’s community banking strategy by increasing its banking network in Oklahoma.

On July 31, 2017, the Company completed a two-for-one stock split of the Company’s outstanding shares of common stock. The stock was payable in the form of a dividend on or about July 31, 2017 to shareholders of record of the outstanding common stock as of the close of business record date of July 17, 2017. Stockholders received one additional share for each share held on that date. This was the second stock split for the Company since going public. All share and per share amounts in these consolidated financial statements and related notes have been retroactively adjusted to reflect this stock split for all periods presented.

Effective June 1, 2017, the Company organized a new wholly-owned captive insurance company named BancFirst Risk & Insurance Company. It insures certain risks of the Company and has entered into reinsurance agreements with a risk-sharing pool.