v3.26.1
Equity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended
Jan. 10, 2025
Jun. 22, 2022
Mar. 31, 2026
Dec. 31, 2025
Class of Stock [Line Items]        
Preferred stock, shares authorized (in shares)     10,000,000  
Preferred stock, par value (in dollars per share)     $ 0  
Dividends paid initial two years   0.00%    
Period of no dividends paid (in years)   2 years    
Review lookback period after year 10, beginning of period   2 years    
Review lookback period after year 10, end of period   10 years    
Spot yield period 20 years      
Equity risk premium percentage 5.00%      
Market beta percentage 0.50%      
Repurchase option description     The POA grants BancPlus a unilateral option to repurchase the Preferred Stock from Treasury over a 15-year period. However, during the first 10 years of this period, exercise of the option is subject to BancPlus satisfying at least one of three “Threshold Conditions” that demonstrate fulfillment of community development and impact lending objectives defined under the ECIP framework. These include the “Deep Impact Lending,” “Qualified Lending,” and “Rate Reduction” thresholds. The Company does not currently meet any of the Threshold Conditions necessary to exercise the purchase option, and there can be no assurance whether and when the Threshold Conditions will be met.  
Minimum        
Class of Stock [Line Items]        
Dividend rate after initial two years   0.50%    
Maximum        
Class of Stock [Line Items]        
Dividend rate after initial two years   2.00%    
Noncumulative Preferred Stock | Private Placement        
Class of Stock [Line Items]        
Shares issued in sale (in shares)   250,000    
Aggregate purchase price of shares   $ 250,000    
Preferred Stock        
Class of Stock [Line Items]        
Dividends payable, preferred stock     $ 139,000 $ 139,000