Annual report pursuant to Section 13 and 15(d)

Allowance for Loan and Lease Losses - Additional Information (Details)

v3.22.0.1
Allowance for Loan and Lease Losses - Additional Information (Details)
12 Months Ended
Feb. 28, 2020
USD ($)
Nov. 15, 2019
USD ($)
Apr. 02, 2019
USD ($)
Dec. 31, 2021
USD ($)
Loan
Dec. 31, 2020
USD ($)
Loan
Dec. 31, 2019
USD ($)
Loan
Financing Receivable Recorded Investment Past Due [Line Items]            
Provision for loan losses       $ 3,711,000 $ 11,257,000 $ 2,856,000
Non-accrual loans, Past due       $ 5,149,000 $ 8,597,000  
Number of restructured loans, defaulted | Loan       0 1 3
Charge-offs due to restructure         $ 85,000 $ 181,000
Covid-19            
Financing Receivable Recorded Investment Past Due [Line Items]            
Description of Loan modifications       Loan modifications made between March 1, 2020 and the earlier of i) 60 days after the end of the national emergency proclamation or ii) December 31, 2020. Section 541 of the Consolidated Appropriations Act of 2021, amended Section 4013 of the CARES Act to extend this relief to the earlier of i) 60 days after the end of the national emergency proclamation or ii) January 1, 2022.    
Loans, payment deferrals days       90 days    
Loans, interest only payment period       90 days    
Payments remaining in deferral       $ 13,900,000    
Financing Receivables, Past Due Greater Than 90 Days or More and Still Accruing            
Financing Receivable Recorded Investment Past Due [Line Items]            
Recorded investment, 90 days past due and still accruing number of loans | Loan       0 0  
Non-accrual loans, Past due       $ 3,700,000 $ 2,200,000  
Financing Receivables, 30 to 59 Days Past Due            
Financing Receivable Recorded Investment Past Due [Line Items]            
Non-accrual loans, Past due       139,000 930,000  
Financing Receivables, 60 to 89 Days Past Due            
Financing Receivable Recorded Investment Past Due [Line Items]            
Non-accrual loans, Past due       16,000 $ 545,000  
Paycheck Protection Loans            
Financing Receivable Recorded Investment Past Due [Line Items]            
Provision for loan losses       $ 0    
Percentage Reserve       0.00%    
Purchased Credit Impaired Loans            
Financing Receivable Recorded Investment Past Due [Line Items]            
Impaired loans       $ 455,000    
Beeville            
Financing Receivable Recorded Investment Past Due [Line Items]            
Business combination loan in acquiree, amount     $ 298,900,000      
Business combination loan In acquiree, fair value     296,400,000      
Business combination loan in acquiree, discount     $ 2,500,000      
Citizens            
Financing Receivable Recorded Investment Past Due [Line Items]            
Business combination loan in acquiree, amount   $ 253,100,000        
Business combination loan In acquiree, fair value   250,300,000        
Business combination loan in acquiree, discount   $ 2,800,000        
Citizens | Purchased Credit Impaired Loans            
Financing Receivable Recorded Investment Past Due [Line Items]            
Impaired loans       3,200,000    
Simmons Bank            
Financing Receivable Recorded Investment Past Due [Line Items]            
Business combination loan in acquiree, amount $ 260,300,000          
Business combination loan In acquiree, fair value 255,500,000          
Business combination loan in acquiree, discount $ 4,800,000          
Beeville or Simmons | Purchased Credit Impaired Loans            
Financing Receivable Recorded Investment Past Due [Line Items]            
Impaired loans       $ 0