|
Note 12 - Stock Options and Employee Stock Purchase Plan (Details) - Stock Option Activity (USD $)
|
1 Months Ended |
12 Months Ended |
|
Mar. 31, 2012
|
Dec. 31, 2014
|
| Stock Option Activity [Abstract] |
|
|
| Outstanding as of December 31, 2013 |
|
1,957,069 |
| Outstanding as of December 31, 2013 |
|
$ 5.48 |
| Granted |
201,000 |
967,903 |
| Granted |
$ 4.20 |
$ 6.70 |
| Exercised |
|
(3,050) |
| Exercised |
|
$ 4.20 |
| Cancelled |
|
(74,825) |
| Cancelled |
|
$ 4.94 |
| Outstanding as of December 31, 2014 |
|
2,847,097 |
| Outstanding as of December 31, 2014 |
|
$ 5.89 |
| Outstanding as of December 31, 2014 |
|
8 years 237 days |
| Outstanding as of December 31, 2014 |
|
$ 11,796,921 |
| Exercisable as of December 31, 2014 |
|
897,294 |
| Exercisable as of December 31, 2014 |
|
$ 5.04 |
| Exercisable as of December 31, 2014 |
|
7 years 197 days |
| Exercisable as of December 31, 2014 |
|
4,509,931 |
| Vested and expected to vest as of December 31, 2014 |
|
2,716,363 |
| Vested and expected to vest as of December 31, 2014 |
|
$ 5.86 |
| Vested and expected to vest as of December 31, 2014 |
|
8 years 226 days |
| Vested and expected to vest as of December 31, 2014 |
|
$ 11,255,225 |