Share-Based Payments (Tables)
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12 Months Ended |
Dec. 31, 2022 |
Share-Based Payment Arrangement [Abstract] |
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Schedule of Share-Based Compensation Expense |
Share-based compensation expense is as follows (dollars in thousands): | | | | | | | | | | | | | | | | | | | Years Ended December 31, | | 2022 | | 2021 | | 2020 | Research and development | $ | 2,922 | | | $ | 2,403 | | | $ | 2,431 | | Selling, general and administrative | 14,646 | | | 15,507 | | | 14,130 | | Total | $ | 17,568 | | | $ | 17,910 | | | $ | 16,561 | |
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Summary of Stock Option and SAR activity |
The following table summarizes stock option and stock appreciation rights (SAR) activities: | | | | | | | | | | | | | | | | | | | | | | | | | Number of Options & SARs | | Weighted Average Exercise Price (per share) | | Weighted Average Remaining Contractual Term (in years) | | Aggregate Intrinsic Value (in thousands) | Outstanding, December 31, 2020 | 5,451,862 | | | $ | 23.26 | | | 6.28 | | $ | 29,877 | | Granted | 1,055,525 | | | $ | 28.93 | | | | | | Exercised | (266,987) | | | $ | 18.47 | | | | | | Forfeited | (466,324) | | | $ | 27.74 | | | | | | Outstanding, December 31, 2021 | 5,774,076 | | | $ | 24.15 | | | 5.95 | | $ | 41,530 | | Granted | 1,103,635 | | | $ | 32.12 | | | | | | Exercised | (817,919) | | | $ | 12.77 | | | | | | Forfeited | (262,223) | | | $ | 30.42 | | | | | | Outstanding, December 31, 2022 | 5,797,569 | | | $ | 26.99 | | | 6.11 | | $ | 53,650 | | As of December 31, 2022 | | | | | | | | Vested and expected to vest | 5,797,569 | | | $ | 26.99 | | | 6.11 | | $ | 53,650 | | Exercisable | 3,541,395 | | | $ | 25.08 | | | 4.68 | | $ | 40,577 | |
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Schedule of Assumptions Used in Estimation of Fair Value of Each Award Option on the Date of Grant Using Black-Scholes Option-Pricing Model |
The fair value of each option award is estimated on the date of the grant, using the Black-Scholes option-pricing model and the assumptions in the following table: | | | | | | | | | | | | | | | | | | | Years Ended December 31, | | 2022 | | 2021 | | 2020 | Fair value of common stock | $28.93 - $35.23 | | $25.09 - $30.45 | | $21.13 - $23.99 | Expected volatility | 58.71% - 60.15% | | 60.62% - 61.80% | | 61.56% - 62.27% | Dividend yield | 0% | | 0% | | 0% | Expected term | 5.58 years - 6.72 years | | 5.63 years - 6.56 years | | 5.72 years - 6.54 years | Risk-free interest rate | 1.87% - 3.70% | | 0.72% - 1.30% | | 0.27% - 1.34% |
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Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity |
The following table summarizes restricted stock unit (RSU) activities: | | | | | | | | | | | | | | | | | | | | | | | | | Number of RSUs | | Weighted- Average Grant Date Fair Value per Share | | Aggregate Intrinsic Value (in thousands) | | Aggregate Fair Value (in thousands) | Nonvested, December 30, 2020 | 26,055 | | | $ | 23.99 | | | | | | Granted | 21,110 | | | $ | 29.61 | | | | | | Vested | (26,055) | | | $ | 23.99 | | | $ | 146.4 | | | $ | 625.1 | | Forfeited | — | | | $ | — | | | | | | Nonvested, December 31, 2021 | 21,110 | | | $ | 29.61 | | | | | | Granted | 134,460 | | | $ | 32.17 | | | | | | Vested | (21,110) | | | $ | 29.61 | | | $ | 69.5 | | | $ | 625.1 | | Forfeited | (2,500) | | | $ | 32.20 | | | | | | Nonvested, December 31, 2022 | 131,960 | | | $ | 32.17 | | | | | |
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Share-Based Payment Arrangement, Performance Shares, Activity |
The following table summarizes performance share unit (PSU) activities: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Performance-Based PSUs | | Market-Based Units | | Total PSUs | | Number of PSUs | | Weighted- Average Grant Date Fair Value per Share | | Number of PSUs | | Weighted- Average Grant Date Fair Value per Share | | Number of PSUs | | Weighted- Average Grant Date Fair Value per Share | Nonvested, December 31, 2020 | — | | | — | | | 15,625 | | | $ | 23.41 | | | 15,625 | | | $ | 23.41 | | Granted | 95,000 | | | $ | 29.74 | | | 20,000 | | | $ | 28.63 | | | 115,000 | | | $ | 29.55 | | Vested | (40,000) | | | $ | 29.61 | | | — | | | $ | — | | | (40,000) | | | $ | 29.61 | | Forfeited | (1,500) | | | $ | 30.45 | | | — | | | $ | — | | | (1,500) | | | $ | 30.45 | | Nonvested, December 31, 2021 | 53,500 | | | $ | 29.82 | | | 35,625 | | | $ | 26.34 | | | 89,125 | | | $ | 28.43 | | Granted | 155,000 | | | $ | 28.93 | | | — | | | $ | — | | | 155,000 | | | $ | 28.93 | | Vested | (22,250) | | | $ | 29.69 | | | (15,625) | | | $ | 23.41 | | | (37,875) | | | $ | 27.10 | | Forfeited | (4,500) | | | $ | 29.94 | | | — | | | $ | — | | | (4,500) | | | $ | 29.94 | | Nonvested, December 31, 2022 | 181,750 | | | $ | 29.07 | | | 20,000 | | | $ | 28.63 | | | 201,750 | | | $ | 29.03 | |
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