v3.26.1
Note 3 - Investment in Westamerica Bancorporation Common Stock - Investments (Details) - EBP 94-2156203 002 [Member] - USD ($)
Dec. 31, 2025
Dec. 31, 2024
Fair value $ 65,827,414 $ 63,548,601
EBP, Employer, Common Stock [Member]    
Number of shares (in shares) 282,987 289,057
Cost $ 13,113,933 $ 13,364,031
Fair value $ 13,535,278 $ 15,163,919