Note 9 - Earnings Per Share - Anti-dilutive Securities (Details) - $ / shares	3 Months Ended	6 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Stock options excluded (in shares)	543,000	620,000	543,000	620,000
Weighted average exercise price of stock options (in dollars per share)	$ 1.75	$ 1.83	$ 1.75	$ 1.83
Average market price of common stock (in dollars per share)	$ 2.79	$ 1.40	$ 2.52	$ 1.37

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration