Note 10 - Earnings (Loss) Per Common Share - Computation of Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2024	Mar. 31, 2023
Net income	$ (4,327)	$ 12,679	$ 4,637	$ (97)	$ 8,352	$ 4,540
Less: Income allocable to unvested restricted stock	0		0		0	0
Income (loss) attributable to common shareholders for diluted earnings (loss) per share	$ (4,327)		$ 4,637		$ 8,352	$ 4,540
Common shares used in basic earnings (loss) per share (in shares)	13,343,793		13,156,715		13,297,324	13,111,866
Common share equivalents outstanding related to RSUs (in shares)	0		0		174,451	0
Total weighted average common shares and common share equivalents used in diluted earnings (loss) per share (in shares)	13,343,793		13,156,715		13,471,775	13,111,866
Basic (in dollars per share)	$ (0.32)		$ 0.35		$ 0.63	$ 0.35
Diluted (in dollars per share)	$ (0.32)		$ 0.35		$ 0.62	$ 0.35