Note 6 - Trade Accounts and Financing Receivable (Details Textual) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, after Allowance for Credit Loss		$ 1,216	$ 8,225
Product [Member]
Disposal Group, Including Discontinued Operation, Consideration	$ 12,500
Promissory Note for Sale of Product [Member]
Financing Receivable, before Allowance for Credit Loss		10,000
Notes Receivable, Interest Rate, Stated Percentage	7.00%
Notes Receivable, Term (Year)	3 years
Notes Receivable, Periodic Payment	$ 300
Proceeds from Collection of Notes Receivable		11,300
Financing Receivable, after Allowance for Credit Loss		$ 1,200