Note 3 - Investment Securities - Schedule of Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Mar. 31, 2024
Amortized cost, as adjusted	$ 144,101	$ 131,106
Gross unrealized holding gains	27	64
Gross unrealized holding losses	(6)	0
Estimated fair value	144,122	131,170
US Government Agencies Debt Securities [Member]
Amortized cost, as adjusted	144,101	131,106
Gross unrealized holding gains	27	64
Gross unrealized holding losses	(6)	0
Estimated fair value	$ 144,122	$ 131,170