v3.26.1
Note 3 - Investment in Westamerica Bancorporation Common Stock (Details Textual)
Dec. 31, 2025
Dec. 31, 2024
EBP, Employer, Common Stock Fund [Member] | EBP 94-2156203 002 [Member]    
EBP, Risk and Uncertainty, Concentration of Investment at Fair Value to Total Investments, Percentage 20.00% 24.00%