v3.26.1
Note 2 - Securities - Changes in the Allowance for Credit Loss on Held to Maturity Securities (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Balance, HTM $ 83 $ 95 $ 95
Provision for credit losses, HTM (15) (7) (12)
Charge-offs of securities, HTM 0 0 0
Recoveries, HTM 0 0 0
Balance, HTM 68 88 83
US Treasury Securities [Member]      
Balance, HTM (0) 0 0
Provision for credit losses, HTM 0 0 0
Charge-offs of securities, HTM 0 0 0
Recoveries, HTM 0 0 0
Balance, HTM (0) 0 (0)
US Agency and Mortgage-backed Securities [Member]      
Balance, HTM (0) 0 0
Provision for credit losses, HTM 0 0 0
Charge-offs of securities, HTM 0 0 0
Recoveries, HTM 0 0 0
Balance, HTM (0) 0 (0)
US States and Political Subdivisions Debt Securities [Member]      
Balance, HTM (0) 0 0
Provision for credit losses, HTM 0 0 0
Charge-offs of securities, HTM 0 0 0
Recoveries, HTM 0 0 0
Balance, HTM (0) 0 (0)
Corporate Debt Securities [Member]      
Balance, HTM 83 95 95
Provision for credit losses, HTM (15) (7) (12)
Charge-offs of securities, HTM 0 0 0
Recoveries, HTM 0 0 0
Balance, HTM $ 68 $ 88 $ 83