Note 15 - Stock-based Compensation (Tables)
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12 Months Ended |
Dec. 31, 2022 |
| Notes Tables |
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| Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] |
| | | December 31, 2022 | | | December 31, 2021 | |
| Cost of goods sold | | $ | — | | | $ | 85 | |
| Research and development | | | 570 | | | | 813 | |
| Selling, general and administrative | | | 2,069 | | | | 2,932 | |
| Discontinued operations | | | 250 | | | | 779 | |
| Total | | $ | 2,889 | | | $ | 4,609 | |
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| 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, 2021 | | | 69,890 | | | $ | 35.75 | |
| Granted | | | 57,448 | | | | 33.65 | |
| Vested | | | (29,338 | ) | | | 37.75 | |
| Forfeited | | | (9,289 | ) | | | 31.56 | |
| Restricted stock units outstanding, December 31, 2021 | | | 88,711 | | | $ | 34.16 | |
| Granted | | | 58,502 | | | | 7.75 | |
| Vested | | | (44,744 | ) | | | 35.46 | |
| Forfeited | | | (19,691 | ) | | | 25.00 | |
| Restricted stock units outstanding, December 31, 2022 | | | 82,778 | | | $ | 16.97 | |
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| 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, 2021 | | | 714,085 | | | $ | 59.79 | | | | | | | | | |
| Granted | | | 117,022 | | | | 7.75 | | | | | | | | | |
| Forfeited | | | (35,645 | ) | | | 26.46 | | | | | | | | | |
| Expired | | | (69,839 | ) | | | 60.42 | | | | | | | | | |
| Exercised | | | — | | | | — | | | | | | | | | |
| December 31, 2022 | | | 725,623 | | | $ | 52.98 | | | | 5.3 | | | $ | — | |
| Vested and exercisable options—December 31, 2022 | | | 515,933 | | | $ | 65.76 | | | | 3.9 | | | $ | — | |
| Vested and expected to vest—December 31, 2022 | | | 725,623 | | | $ | 52.80 | | | | 5.3 | | | $ | — | |
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| 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 | |
| $4.62 | - | $8.03 | | | 88,096 | | | | 9.2 | | | $ | 7.54 | | | | — | | | $ | — | |
| $8.36 | - | $12.54 | | | 19,046 | | | | 9.1 | | | $ | 8.43 | | | | — | | | $ | — | |
| $14.40 | - | $21.60 | | | 20,941 | | | | 6.9 | | | $ | 16.93 | | | | 13,643 | | | $ | 16.84 | |
| $22.40 | - | $33.60 | | | 11,700 | | | | 8.1 | | | $ | 28.62 | | | | 10,774 | | | $ | 28.58 | |
| $34.40 | - | $51.60 | | | 311,695 | | | | 6.0 | | | $ | 41.16 | | | | 217,425 | | | $ | 42.75 | |
| $52.00 | - | $78.00 | | | 168,275 | | | | 3.5 | | | $ | 62.66 | | | | 168,221 | | | $ | 62.66 | |
| $78.40 | - | $117.60 | | | 62,756 | | | | 1.0 | | | $ | 97.95 | | | | 62,756 | | | $ | 97.95 | |
| $132.00 | - | $198.00 | | | 20,520 | | | | 1.6 | | | $ | 133.16 | | | | 20,520 | | | $ | 133.16 | |
| $204.40 | - | $306.60 | | | 22,594 | | | | 1.0 | | | $ | 206.96 | | | | 22,594 | | | $ | 206.96 | |
| | | | | | 725,623 | | | | 5.3 | | | $ | 52.98 | | | | 515,933 | | | $ | 65.76 | |
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| Time-based Stock Option [Member] |
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| Notes Tables |
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| Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |
| | | Year Ended December 31, | |
| | | 2022 | | | 2021 | |
| Expected term (in years) | | 6.3 | | | 6.0 | - | 6.2 | |
| Risk-free interest rate | | 1.6% | - | 3.0% | | | 0.9% | - | 1.3% | |
| Expected volatility | | 88% | | | 90% | |
| Expected dividend rate | | 0% | | | 0% | |
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| Performance Shares [Member] |
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| Notes Tables |
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| Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |
| | | Year Ended December 31, | |
| | | 2022 | | | 2021 | |
| 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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