Note 2 - Summary of Significant Accounting Policies - Debt Securities by Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Within one year, amortized cost	$ 11,000
Within one year, fair value	10,958
After one year through two years, amortized cost	9,950
After one year through two years, fair value	9,882
Amortized cost	20,950	$ 19,933
Fair value	$ 20,840	$ 20,009