Note 11 - Stock-based Compensation - Compensation Expense Related to Stock Options (Details) - Share-based Payment Arrangement, Option [Member] - USD ($)	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Compensation expense	$ 146,792	$ 43,924	$ 66,243
Fiscal Year 2012 [Member]
Compensation expense			5,359
Fiscal Year 2014 [Member]
Compensation expense			13,575
Fiscal Year 2016 [Member]
Compensation expense		1,789	16,221
Fiscal Year 2017 [Member]
Compensation expense	18,377	42,135	31,088
Fiscal Year 2019 [Member]
Compensation expense	$ 128,415

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration