Note 15 - Stock Compensation Plan - Summary of Stock Options Outstanding and Exercisable by Ranges of Option Prices (Details)
|
12 Months Ended |
|
Dec. 31, 2016
$ / shares
shares
|
|---|
| Number of options outstanding (in shares) | shares |
47,582,402
|
| Number of options exercisable (in shares) | shares |
22,419,208
|
| Exercise Price Range 1 [Member] |
|
| Range of exercise prices, lower (in dollars per share) |
$ 0
|
| Range of exercise prices, upper (in dollars per share) |
$ 0.10
|
| Number of options outstanding (in shares) | shares |
20,603,777
|
| Options outstanding, weighted average remaining contractual life (Year) |
7 years 102 days
|
| Options outstanding, weighted average exercise price (in dollars per share) |
$ 0.07
|
| Number of options exercisable (in shares) | shares |
8,132,001
|
| Options exercisable, weighted average remaining contractual life (Year) |
4 years 354 days
|
| Options exercisable, weighted average exercise price (in dollars per share) |
$ 0.08
|
| Exercise Price Range 2 [Member] |
|
| Range of exercise prices, lower (in dollars per share) |
0.011
|
| Range of exercise prices, upper (in dollars per share) |
$ 0.772
|
| Number of options outstanding (in shares) | shares |
26,978,625
|
| Options outstanding, weighted average remaining contractual life (Year) |
7 years 146 days
|
| Options outstanding, weighted average exercise price (in dollars per share) |
$ 0.21
|
| Number of options exercisable (in shares) | shares |
14,287,207
|
| Options exercisable, weighted average remaining contractual life (Year) |
6 years 277 days
|
| Options exercisable, weighted average exercise price (in dollars per share) |
$ 0.22
|