Note 2 - Shareholders' Equity - Options Exercisable (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
|
| Exercisable (in shares) | 51,201 | 97,333 |
| Weighted average remaining contractual life (Year) | 2 years 3 months 14 days | 2 years 2 months 8 days |
| Weighted average exercise price (in dollars per share) | $ 12.28 | $ 12.76 |
| Aggregate intrinsic value | $ 1,631,575 | $ 720,826 |
| X | ||||||||||
- Definition The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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