Note 4 - Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Net income	$ 46,444	$ 33,935	$ 23,243
Weighted average number of shares of common stock outstanding (in shares)	22,936,194	22,774,825	22,725,088
Effect of dilutive securities (in shares)	319,080	309,078	109,228
Weighted average number of shares of common stock outstanding including the effect of dilutive securities (in shares)	23,255,274	23,083,903	22,834,316
Basic earnings per share (in dollars per share)	$ 2.02	$ 1.49	$ 1.02
Diluted earnings per share (in dollars per share)	$ 2	$ 1.47	$ 1.02