Note 3 - Accounts Receivable Agreements (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019
Restricted Cash, Total	$ 104,300		$ 104,300		$ 351,909
Certain Receivables to Unrelated Third-parties [Member]
Accounts Receivable Agreement, Percent of Sold Receivables Advanced	90.00%		90.00%
Accounts Receivable Agreement, Reserve of Sold Receivables	10.00%		10.00%
Restricted Cash, Total	$ 100,000		$ 100,000
Accounts Receivable, after Allowance for Credit Loss, Total	800,000		800,000
Sale of Receivables, Maximum Limit of Receivables Uncollected	4,000,000		4,000,000
Proceeds from Collection of Finance Receivables			11,400,000	$ 2,900,000
Certain Receivables to Unrelated Third-parties [Member] | Other Nonoperating Income (Expense) [Member]
Cost of Selling Receivables	$ 100,000	$ 100,000	$ 200,000	$ 100,000
Certain Receivables to Unrelated Third-parties [Member] | Minimum [Member]
Receivables, Cost of Sales, Percent			1.00%	1.70%
Certain Receivables to Unrelated Third-parties [Member] | Maximum [Member]
Receivables, Cost of Sales, Percent			1.80%	1.90%