Note 5 - Stock-based Compensation (Details Textual) shares in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) shares	Sep. 30, 2023 shares	Mar. 31, 2023 USD ($) shares
Number of Stock-based Compensation Plans in Effect	2
Share-Based Payment Arrangement, Expense	$ 160,000		$ 0
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares) | shares	0		0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Expirations in Period (in shares) | shares		0	0
Restricted Stock Units (RSUs) [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 3,100,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	2 years 10 months 24 days