Note 2 - Revenue Recognition - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Total revenue	$ 31,370	$ 24,700	$ 62,479	$ 42,691
Product [Member]
Total revenue	17,701	21,565	37,249	34,597
Asia [Member] | Product [Member]
Total revenue	1,443	1,679	7,977	6,357
CANADA | Product [Member]
Total revenue	333	659	1,094	1,057
Europe [Member] | Product [Member]
Total revenue	1,792	11,432	2,926	12,743
UNITED STATES | Product [Member]
Total revenue	13,479	7,305	24,070	13,324
Other [Member] | Product [Member]
Total revenue	$ 654	$ 490	$ 1,182	$ 1,116