v3.26.1
Significant Accounting Policies (Details)
3 Months Ended 6 Months Ended
Jun. 16, 2026
USD ($)
Jun. 11, 2026
USD ($)
$ / shares
shares
Jun. 30, 2026
USD ($)
shares
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
segment
shares
Jun. 30, 2025
USD ($)
Mar. 31, 2026
USD ($)
Dec. 31, 2025
USD ($)
shares
Sale of Stock [Line Items]                
Common stock, issued (in shares) | shares     7,628,809   7,628,809     7,322,207
Common stock, outstanding (in shares) | shares     7,628,809   7,628,809     7,322,207
Total assets     $ 2,219,641,000   $ 2,219,641,000     $ 2,209,448,000
Total loans     1,575,193,000   1,575,193,000     1,522,637,000
Total deposits     1,809,913,000   1,809,913,000     $ 1,819,654,000
Pro forma information, assets   $ 2,700,000,000            
Merger-related expenses     $ 505,000 $ 0 $ 505,000 $ 0    
Number of operating segments | segment         1      
Number of reportable segments | segment         1      
Grand River                
Sale of Stock [Line Items]                
Total assets             $ 511,700,000  
Total loans             433,000,000.0  
Total deposits             $ 438,900,000  
Grand River                
Sale of Stock [Line Items]                
Merger agreement, aggregate cash consideration   $ 18,262,391            
Merger agreement, cash conversion multiple   0.35            
Merger agreement, Isabella common stock included in calculation of exchange ratio (in shares) | shares   839,003            
Merger agreement, shares exchanged for per share stock consideration (percent)   65.00%            
Merger agreement, shares exchanged for per share cash consideration (percent)   35.00%            
Common stock, issued (in shares) | shares   9,136,529            
Common stock, outstanding (in shares) | shares   9,136,529            
Price per share (in dollars per share) | $ / shares   $ 5.71            
Merger agreement, exchange ratio   0.1413            
Piper Sandler & Co. Equity Distribution Agreement                
Sale of Stock [Line Items]                
Sale of stock, aggregate gross sales price $ 30,000,000.0              
Sale of stock, agent commission (percent) 3.00%