Note 2 - Summary of Significant Accounting Policies - Debt Securities by Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Within one year, amortized cost	$ 9,968
Within one year, fair value	9,984
After one year through two years, amortized cost	8,400
After one year through two years, fair value	8,423
After two years through three years, amortized cost	981
After two years through three years, fair value	989
Amortized cost	19,349	$ 21,059
Fair value	$ 19,396	$ 21,076