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Stock-based Compensation - Employee Stock Purchase Plan (Details) - USD ($) $ in Thousands | 1 Months Ended | 12 Months Ended |
--- | --- | --- | ---
May 31, 2017 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | May 18, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Proceeds from issuance of common stock, net of offering costs |  | $ 117,818 | $ 170,456 | $ 118,657 |
Employee Stock |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Offering period | 6 months |  |  |  |
2016 Employee Stock Purchase Plan |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Share-based compensation, number of shares authorized (in shares) |  |  |  |  | 800,000
Maximum employee contribution percent | 10.00% |  |  |  |
Percent of fair market value to purchase shares | 85.00% |  |  |  |
Common stock purchased by employees (in shares) |  | 34,922 |  |  |
Proceeds from issuance of common stock, net of offering costs |  | $ 700 |  |  |

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