Note 11 - Net Loss Per Share - Schedule of Antidilutive Shares Excluded from Computation of Net Loss Per Share (Details) - shares |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| Employee and Non-employee Stock Options [Member] | ||||
| Employee and non-employee stock options (in shares) | 1,249,559 | 627,484 | 1,249,559 | 627,484 |
| Warrant [Member] | ||||
| Employee and non-employee stock options (in shares) | 807,563 | 831,251 | 807,563 | 831,251 |
| Deferred Share Units [Member] | ||||
| Employee and non-employee stock options (in shares) | 21,183 | 21,183 | 21,183 | 21,183 |