Note 3 - Cash, Cash Equivalents and Investments - Maturity Date of CDs (Details) - USD ($) |
Jun. 30, 2020 |
Sep. 30, 2019 |
|---|---|---|
| Less than one year | $ 11,093,527 | $ 13,524,270 |
| 1-5 years | 28,072,000 | 23,902,000 |
| Total | $ 39,165,527 | $ 37,426,270 |
| X | ||||||||||
- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|