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Stock Incentive Plan and Other Equity Activity (Details) - USD ($) shares in Thousands, $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Sale of Stock [Line Items] |  |  |  |  |  |  |  |
Stock-based compensation expense | $ 1,765 |  |  | $ 819 |  |  | $ 7,961 | $ 2,489
Shares withheld for taxes | $ (133) | $ (50) | $ (772) | (32) | $ (98) | $ (564) |  |
Shares issued from warrants (in shares) | 110 |  |  |  |  |  | 110 |
Number of warrants exercised (in shares) | 470 |  |  |  |  |  | 470 |
Fair value of warrants exercised |  |  |  |  |  |  | $ 1,477 |
Employee Stock Purchase Plan | ESPP |  |  |  |  |  |  |  |
Sale of Stock [Line Items] |  |  |  |  |  |  |  |
Stock-based compensation expense | $ 18 |  |  | $ 12 |  |  | $ 54 | $ 12
Remaining authorized shares available for purchase (in shares) | 754 |  |  |  |  |  | 754 |
Treasury Stock |  |  |  |  |  |  |  |
Sale of Stock [Line Items] |  |  |  |  |  |  |  |
Shares withheld for taxes (in shares) | 14 | 3 | 46 | 3 |  | 45 |  |
Shares withheld for taxes | $ (133) | $ (32) | $ (668) | $ (32) |  | $ (564) |  |
Treasury Stock | RSU/PSU |  |  |  |  |  |  |  |
Sale of Stock [Line Items] |  |  |  |  |  |  |  |
Shares withheld for taxes (in shares) | 11 |  |  |  |  |  | 60 |
Shares withheld for taxes | $ 105 |  |  |  |  |  | $ 805 |
Treasury Stock | RSAs |  |  |  |  |  |  |  |
Sale of Stock [Line Items] |  |  |  |  |  |  |  |
Shares withheld for taxes (in shares) | 3 |  |  |  |  |  | 13 |
Shares withheld for taxes | $ 28 |  |  |  |  |  | $ 150 |

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