v3.26.1
Fair Values of Financial Instruments (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Financial assets:    
Cash and due from banks $ 47,964 $ 51,665
Interest earning deposits with financial institutions 95,369 72,360
Securities available-for-sale, at fair value 1,040,760 1,090,523
FHLBC and FRBC Stock 40,125 32,025
Mortgage servicing rights 9,825 9,459
Financial liabilities:    
Noninterest bearing deposits 1,746,755 1,739,117
Other short-term borrowings 375,000 215,000
Junior subordinated debentures 25,774 25,774
Notes payable and other borrowings 14,850 14,825
Reported Value Measurement    
Financial assets:    
Cash and due from banks 47,964 51,665
Interest earning deposits with financial institutions 95,369 72,360
Securities available-for-sale, at fair value 1,040,760 1,090,523
FHLBC and FRBC Stock 40,125 32,025
Loans held for sale 2,349 3,645
Net loans 5,175,490 5,179,830
Mortgage servicing rights 9,825 9,459
Interest rate swap and rate cap agreements 3,837 4,298
Interest rate lock commitments and forward contracts   31
Interest receivable on securities and loans 29,562 30,344
Financial liabilities:    
Noninterest bearing deposits 1,746,755 1,739,117
Interest bearing deposits 3,697,933 3,856,952
Securities sold under repurchase agreements 23,241 23,769
Other short-term borrowings 375,000 215,000
Junior subordinated debentures 25,774 25,774
Subordinated debentures 29,798 59,552
Notes payable and other borrowings 14,850 14,825
Interest rate swap and rate cap agreements 468 1,143
Interest rate lock commitments and forward contracts 12  
Interest payable on deposits and borrowings 4,183 5,451
Estimate of Fair Value Measurement    
Financial assets:    
Cash and due from banks 47,964 51,665
Interest earning deposits with financial institutions 95,369 72,360
Securities available-for-sale, at fair value 1,040,760 1,090,523
FHLBC and FRBC Stock 40,125 32,025
Loans held for sale 2,349 3,645
Net loans 5,092,909 5,032,472
Mortgage servicing rights 9,825 9,459
Interest rate swap and rate cap agreements 3,837 4,298
Interest rate lock commitments and forward contracts   31
Interest receivable on securities and loans 29,562 30,344
Financial liabilities:    
Noninterest bearing deposits 1,746,755 1,739,117
Interest bearing deposits 3,690,225 3,850,530
Securities sold under repurchase agreements 23,241 23,769
Other short-term borrowings 375,000 215,000
Junior subordinated debentures 21,779 21,522
Subordinated debentures 28,748 57,973
Notes payable and other borrowings 14,921 15,049
Interest rate swap and rate cap agreements 468 1,143
Interest rate lock commitments and forward contracts 12  
Interest payable on deposits and borrowings 4,183 5,451
Fair Value, Inputs, Level 1    
Financial assets:    
Cash and due from banks 47,964 51,665
Interest earning deposits with financial institutions 95,369 72,360
Securities available-for-sale, at fair value 144,387 165,860
Financial liabilities:    
Noninterest bearing deposits 1,746,755 1,739,117
Fair Value, Inputs, Level 2    
Financial assets:    
Securities available-for-sale, at fair value 884,490 912,866
FHLBC and FRBC Stock 40,125 32,025
Loans held for sale 2,349 3,645
Interest rate swap and rate cap agreements 3,837 4,298
Interest rate lock commitments and forward contracts   31
Interest receivable on securities and loans 29,562 30,344
Financial liabilities:    
Interest bearing deposits 3,690,225 3,850,530
Securities sold under repurchase agreements 23,241 23,769
Other short-term borrowings 375,000 215,000
Junior subordinated debentures 21,779 21,522
Subordinated debentures 28,748 57,973
Notes payable and other borrowings 14,921 15,049
Interest rate swap and rate cap agreements 468 1,143
Interest rate lock commitments and forward contracts 12  
Interest payable on deposits and borrowings 4,183 5,451
Fair Value, Inputs, Level 3    
Financial assets:    
Securities available-for-sale, at fair value 11,883 11,797
Net loans 5,092,909 5,032,472
Mortgage servicing rights $ 9,825 $ 9,459