v3.26.1
Loans - Allowance for Credit Losses (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Allowance for Credit Losses [Roll Forward]          
Beginning Balance $ 78,547 $ 75,158 $ 77,694 $ 44,436 $ 44,436
Change in Accounting Method       (7)  
2/1/2025 Acquired Heartland PCD       15,908  
Day 2 CECL Provision - Heartland       16,200  
Provision (Benefit) for Credit Loss Expense 1,500 1,200 3,500 16,500  
Provision (Benefit) for Credit Loss Expense   1,200   307  
Loans Charged-off (945) (1,021) (2,413) (1,646)  
Recoveries Collected 272 173 593 312  
Total Ending Allowance Balance 79,374 75,510 79,374 75,510 77,694
Excluding Heartland Acquisition          
Allowance for Credit Losses [Roll Forward]          
Provision (Benefit) for Credit Loss Expense     3,500    
Commercial and Industrial Loans          
Allowance for Credit Losses [Roll Forward]          
Beginning Balance 18,676 15,343 19,576 7,059 7,059
Change in Accounting Method       1,438  
2/1/2025 Acquired Heartland PCD       5,246  
Day 2 CECL Provision - Heartland       1,797  
Provision (Benefit) for Credit Loss Expense (1,071)        
Provision (Benefit) for Credit Loss Expense   2,620   2,545  
Loans Charged-off 0 (247) (488) (373) (764)
Recoveries Collected 21 23 23 27  
Total Ending Allowance Balance 17,626 17,739 17,626 17,739 19,576
Commercial and Industrial Loans | Excluding Heartland Acquisition          
Allowance for Credit Losses [Roll Forward]          
Provision (Benefit) for Credit Loss Expense     (1,485)    
Commercial Real Estate Loans          
Allowance for Credit Losses [Roll Forward]          
Beginning Balance 42,150 37,811 40,626 25,818 25,818
Change in Accounting Method       (3,271)  
2/1/2025 Acquired Heartland PCD       7,080  
Day 2 CECL Provision - Heartland       7,522  
Provision (Benefit) for Credit Loss Expense 1,550        
Provision (Benefit) for Credit Loss Expense   423   1,085  
Loans Charged-off 0 (26) 0 (26) (26)
Recoveries Collected 0 0 37 0  
Total Ending Allowance Balance 43,700 38,208 43,700 38,208 40,626
Commercial Real Estate Loans | Excluding Heartland Acquisition          
Allowance for Credit Losses [Roll Forward]          
Provision (Benefit) for Credit Loss Expense     3,037    
Agricultural Loans          
Allowance for Credit Losses [Roll Forward]          
Beginning Balance 3,244 5,306 3,324 4,917 4,917
Change in Accounting Method       (1,655)  
2/1/2025 Acquired Heartland PCD       3,352  
Day 2 CECL Provision - Heartland       170  
Provision (Benefit) for Credit Loss Expense 99        
Provision (Benefit) for Credit Loss Expense   (2,176)   (3,654)  
Loans Charged-off 0 0 0 0 (8)
Recoveries Collected 0 0 0 0  
Total Ending Allowance Balance 3,343 3,130 3,343 3,130 3,324
Agricultural Loans | Excluding Heartland Acquisition          
Allowance for Credit Losses [Roll Forward]          
Provision (Benefit) for Credit Loss Expense     19    
Leases          
Allowance for Credit Losses [Roll Forward]          
Beginning Balance 1,171 1,151 1,178 397 397
Change in Accounting Method       720  
2/1/2025 Acquired Heartland PCD       0  
Day 2 CECL Provision - Heartland       0  
Provision (Benefit) for Credit Loss Expense 29        
Provision (Benefit) for Credit Loss Expense   41   75  
Loans Charged-off 0 0 (149) 0 0
Recoveries Collected 0 0 0 0  
Total Ending Allowance Balance 1,200 1,192 1,200 1,192 1,178
Leases | Excluding Heartland Acquisition          
Allowance for Credit Losses [Roll Forward]          
Provision (Benefit) for Credit Loss Expense     171    
Consumer Loans          
Allowance for Credit Losses [Roll Forward]          
Beginning Balance 655 657 687 727 727
Change in Accounting Method       (284)  
2/1/2025 Acquired Heartland PCD       20  
Day 2 CECL Provision - Heartland       179  
Provision (Benefit) for Credit Loss Expense 360        
Provision (Benefit) for Credit Loss Expense   259   486  
Loans Charged-off (596) (334) (991) (659) (1,667)
Recoveries Collected 224 109 401 222  
Total Ending Allowance Balance 643 691 643 691 687
Consumer Loans | Excluding Heartland Acquisition          
Allowance for Credit Losses [Roll Forward]          
Provision (Benefit) for Credit Loss Expense     546    
Home Equity Loans          
Allowance for Credit Losses [Roll Forward]          
Beginning Balance 4,291 3,942 4,065 2,196 2,196
Change in Accounting Method       1,056  
2/1/2025 Acquired Heartland PCD       11  
Day 2 CECL Provision - Heartland       570  
Provision (Benefit) for Credit Loss Expense 248        
Provision (Benefit) for Credit Loss Expense   384   492  
Loans Charged-off (112) 0 (112) 0 (96)
Recoveries Collected 15 8 19 9  
Total Ending Allowance Balance 4,442 4,334 4,442 4,334 4,065
Home Equity Loans | Excluding Heartland Acquisition          
Allowance for Credit Losses [Roll Forward]          
Provision (Benefit) for Credit Loss Expense     470    
Credit Cards          
Allowance for Credit Losses [Roll Forward]          
Beginning Balance 576 608 600 520 520
Change in Accounting Method       (24)  
2/1/2025 Acquired Heartland PCD       0  
Day 2 CECL Provision - Heartland       0  
Provision (Benefit) for Credit Loss Expense 177        
Provision (Benefit) for Credit Loss Expense   366   631  
Loans Charged-off (205) (386) (531) (560)  
Recoveries Collected 12 33 113 54  
Total Ending Allowance Balance 560 621 560 621 600
Credit Cards | Excluding Heartland Acquisition          
Allowance for Credit Losses [Roll Forward]          
Provision (Benefit) for Credit Loss Expense     378    
Residential Mortgage Loans          
Allowance for Credit Losses [Roll Forward]          
Beginning Balance 7,784 10,340 7,638 2,802 2,802
Change in Accounting Method       2,013  
2/1/2025 Acquired Heartland PCD       199  
Day 2 CECL Provision - Heartland       5,962  
Provision (Benefit) for Credit Loss Expense 108        
Provision (Benefit) for Credit Loss Expense   (717)   (1,353)  
Loans Charged-off (32) (28) (142) (28) (114)
Recoveries Collected 0 0 0 0  
Total Ending Allowance Balance $ 7,860 $ 9,595 7,860 $ 9,595 $ 7,638
Residential Mortgage Loans | Excluding Heartland Acquisition          
Allowance for Credit Losses [Roll Forward]          
Provision (Benefit) for Credit Loss Expense     $ 364