Note 3 - Cash, Cash Equivalents and Investments - CD Maturity Dates (Details) - USD ($) |
Mar. 31, 2018 |
Sep. 30, 2017 |
|---|---|---|
| Less than one year | $ 6,285,225 | $ 5,937,150 |
| 1-5 years | 20,180,000 | 19,816,000 |
| Total | $ 26,465,225 | $ 25,753,150 |
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- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- 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 through fifth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| 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 latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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