Consolidated Balance Sheets (Parentheticals) - $ / shares |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Series A preferred stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
| Series A preferred stock, shares authorized (in shares) | 50,000 | 50,000 |
| Series A preferred stock, shares issued (in shares) | 0 | 0 |
| Series A preferred stock, shares outstanding (in shares) | 0 | 0 |
| Common stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
| Common stock, shares authorized (in shares) | 20,000,000 | 20,000,000 |
| Common stock, shares issued (in shares) | 13,317,393 | 13,070,180 |
| Common stock, shares outstanding (in shares) | 13,020,889 | 12,536,180 |