Note 1 - Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Sep. 30, 2022 |
Sep. 30, 2021 |
|
| Balance at Beginning of Year | $ 79,000 | $ 289,000 |
| Additions Charged to Costs and Expenses | 0 | (210,000) |
| Less Write-offs | 0 | 0 |
| Balance at End of Year | $ 79,000 | $ 79,000 |
| X | ||||||||||
- Definition Amount of allowance for credit loss on accounts receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of increase (decrease) in allowance for credit loss on accounts receivable. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of direct write-downs of accounts receivable charged against the allowance. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|