Note 14 - Stock Based Compensation (Tables)
|
12 Months Ended |
Dec. 31, 2021 |
|---|
| Notes Tables |
|
| Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] |
| | | December 31,
2021 | | | December 31,
2020 | |
| Cost of goods sold | | $ | 92 | | | $ | 123 | |
| Research and development | | | 813 | | | | 764 | |
| Selling, general and administrative | | | 3,704 | | | | 3,537 | |
| Total | | $ | 4,609 | | | $ | 4,424 | |
|
| Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] |
| | | | | | | Weighted | |
| | | Number of | | | Average | |
| | | Restricted | | | Grant Date | |
| | | Stock Units | | | Fair Value | |
| Restricted stock units outstanding, January 1, 2020 | | | 988,645 | | | $ | 2.53 | |
| Granted | | | 908,300 | | | | 1.30 | |
| Vested | | | (304,810 | ) | | | 2.53 | |
| Forfeited | | | (194,152 | ) | | | 2.16 | |
| Restricted stock units outstanding, December 31, 2020 | | | 1,397,983 | | | $ | 1.79 | |
| Granted | | | 1,149,632 | | | | 1.68 | |
| Vested | | | (587,214 | ) | | | 1.89 | |
| Forfeited | | | (186,025 | ) | | | 1.58 | |
| Restricted stock units outstanding, December 31, 2021 | | | 1,774,376 | | | $ | 1.71 | |
|
| Share-based Payment Arrangement, Option, Activity [Table Text Block] |
| | | Number
of Stock Options
Outstanding | | | Weighted-
Average
Exercise
Price | | | Weighted-
Average
Remaining
Contractual
Life (Years) | | | Aggregate
Intrinsic
Value | |
| | | | | | | | | | | | | | | (in thousands) | |
| December 31, 2020 | | | 12,813,022 | | | $ | 3.20 | | | | | | | | | |
| Granted | | | 2,667,612 | | | | 1.82 | | | | | | | | | |
| Forfeited | | | (375,432 | ) | | | 1.79 | | | | | | | | | |
| Expired | | | (801,749 | ) | | | 3.03 | | | | | | | | | |
| Exercised | | | (19,403 | ) | | | 0.84 | | | | | | | | | |
| December 31, 2021 | | | 14,284,050 | | | $ | 2.99 | | | | 5.8 | | | $ | — | |
| Vested and exercisable options—December 31, 2021 | | | 10,496,744 | | | $ | 3.42 | | | | 4.8 | | | $ | — | |
| Vested and expected to vest—December 31, 2021 | | | 14,284,050 | | | $ | 2.99 | | | | 5.8 | | | $ | — | |
|
| Schedule of Share-based Compensation, Stock Options Outstanding and Exercisable Activity [Table Text Block] |
| | | | | Options Outstanding | | | Options Vested and Exercisable | |
| Exercise Prices | | Number of
Stock Options
Outstanding | | | Weighted-Average
Remaining
Contractual Life
(Years) | | | Weighted-Average
Exercise Price per
Share | | | Shares Subject
to Stock
Options | | | Weighted-Average
Exercise Price per
Share | |
| $0.72 | - | $1.12 | | | 695,482 | | | | 8.1 | | | $ | 0.85 | | | | 280,047 | | | $ | 0.84 | |
| $1.26 | - | $1.89 | | | 3,402,418 | | | | 8.9 | | | $ | 1.80 | | | | 496,679 | | | $ | 1.67 | |
| $2.00 | - | $3.00 | | | 5,310,550 | | | | 6.1 | | | $ | 2.44 | | | | 4,856,618 | | | $ | 2.43 | |
| $3.10 | - | $4.65 | | | 3,066,819 | | | | 3.8 | | | $ | 3.37 | | | | 3,054,619 | | | $ | 3.38 | |
| $4.73 | - | $7.10 | | | 1,295,781 | | | | 1.8 | | | $ | 5.71 | | | | 1,295,781 | | | $ | 5.71 | |
| $8.18 | - | $12.27 | | | 513,000 | | | | 2.1 | | | $ | 10.28 | | | | 513,000 | | | $ | 10.28 | |
| | | | | | 14,284,050 | | | | 5.8 | | | $ | 2.99 | | | | 10,496,744 | | | $ | 3.42 | |
|
| Time-based Stock Option [Member] |
|
| Notes Tables |
|
| Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |
| | | Year Ended December 31, | |
| | | 2021 | | 2020 | |
| Expected term (in years) | | | 6.0 | - | 6.2 | | | | | 6.2 | | |
| Risk-free interest rate | | | 0.9% | - | 1.3% | | | | 0.4% | - | 1.5% | |
| Expected volatility | | | | 90% | | | | | | 83% | | |
| Expected dividend rate | | | | 0% | | | | | | 0% | | |
|
| Performance Shares [Member] |
|
| Notes Tables |
|
| Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |
| | | Year Ended December 31, | |
| | | 2021 | | | 2020 | |
| Derived service period (in years) | | 2.3 | – | 2.6 | | | | — | |
| Risk-free interest rate | | | 1.5% | | | | | — | |
| Expected volatility | | | 90% | | | | | — | |
| Expected dividend rate | | | 0% | | | | | — | |
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