XML 108 R95.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stockholders' Equity - Additional Information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2018
Jan. 01, 2019
Dec. 31, 2017
2016 [Member]      
Stockholders Equity [Line Items]      
Implementation of the capital conservation buffer, Percentage 0.625%    
Capital conservation buffer implementation phase-in period 4 years    
2019 [Member]      
Stockholders Equity [Line Items]      
Capital Conservation Buffer Maximum Level 2.50%    
Maximum [Member]      
Stockholders Equity [Line Items]      
Quantitative limit for trust preferred securities to be included in tier 1 capital $ 15,000,000,000    
Subsequent Event [Member]      
Stockholders Equity [Line Items]      
Available equity of BancFirst for dividend payments to the company   $ 140,300,000  
Senior Preferred Stock [Member]      
Stockholders Equity [Line Items]      
Preferred stock, shares issued 0   0
Preferred stock, shares outstanding 0    
Cumulative Preferred Stock [Member]      
Stockholders Equity [Line Items]      
Preferred stock, shares issued 0   0
Preferred stock, shares outstanding 0    
Dividend payable at redemption, per share $ 5.00    
Cumulative preferred stock dividend rate 10.00%