Note 4 - Fair Values of Financial Instruments - Assets and Liabilities at Fair Value on a Recurring Basis (Details) - USD ($) |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Investment securities, available for sale | $ 10,799,890 | |
| Earn-out milestone liability | $ 13,188,226 | 13,921,412 |
| Fair Value, Measurements, Recurring [Member] | ||
| Investment securities, available for sale | 1,680,000 | 10,799,890 |
| Earn-out milestone liability | 13,188,226 | 13,921,412 |
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ||
| Investment securities, available for sale | 1,680,000 | 10,799,890 |
| Earn-out milestone liability | ||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ||
| Investment securities, available for sale | ||
| Earn-out milestone liability | $ 13,188,226 | $ 13,921,412 |