Note 2 - Summary of Significant Accounting Policies - Debt Securities by Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Within one year, amortized cost	$ 12,420
Within one year, fair value	12,455
After one year through two years, amortized cost	6,943
After one year through two years, fair value	6,955
After two years through three years, amortized cost	982
After two years through three years, fair value	995
Amortized cost	20,345	$ 21,059
Fair value	$ 20,405	$ 21,076