Note 8 - Equity - Stock Options Activity (Details) - $ / shares
|
12 Months Ended |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Granted at Market Price, Number of Shares (in shares) |
660,000
|
240,160
|
|
| Exercised, Number of Shares (in shares) |
(70,931)
|
(534)
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross |
660,000
|
240,160
|
|
| Employee Stock Option [Member] |
|
|
|
| Outstanding, Number of Shares (in shares) |
477,459
|
314,775
|
|
| Outstanding, Weighted Average Exercise Price (in dollars per share) |
$ 4.30
|
$ 2.23
|
|
| Outstanding, Weighted Average Fair Value (in dollars per share) |
$ 1.86
|
$ 2.01
|
$ 0.92
|
| Outstanding, Weighted Average Remaining Contractual Life (Year) |
6 years 328 days
|
8 years 255 days
|
9 years 73 days
|
| Granted at Market Price, Number of Shares (in shares) |
660,000
|
240,160
|
|
| Granted at Market Price, Weighted Average Exercise Price (in dollars per share) |
$ 3.22
|
$ 8.16
|
|
| Exercised, Number of Shares (in shares) |
(37,824)
|
(445)
|
|
| Exercised, Weighted Average Exercise Price (in dollars per share) |
$ 1.88
|
$ 1.20
|
|
| Cancelled, Number of Shares (in shares) |
(146,560)
|
(77,031)
|
|
| Cancelled, Weighted Average Exercise Price (in dollars per share) |
$ 4.34
|
$ 7.88
|
|
| Outstanding, Number of Shares (in shares) |
953,075
|
477,459
|
314,775
|
| Outstanding, Weighted Average Exercise Price (in dollars per share) |
$ 3.66
|
$ 4.30
|
$ 2.23
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross |
660,000
|
240,160
|
|
| Granted at Market Price, Weighted Average Exercise Price (in dollars per share) |
$ 3.22
|
$ 8.16
|
|
| Exercised, Weighted Average Exercise Price (in dollars per share) |
1.88
|
1.20
|
|
| Cancelled, Weighted Average Exercise Price (in dollars per share) |
$ 4.34
|
$ 7.88
|
|
| Exercisable, Number of Shares (in shares) |
347,272
|
|
|
| Exercisable, Weighted Average Exercise Price (in dollars per share) |
$ 4.07
|
|
|
| Exercisable, Weighted Average Fair Value (in dollars per share) |
$ 2.38
|
|
|
| Exercisable, Weighted Average Remaining Contractual Life (Year) |
3 years 328 days
|
|
|