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Employee Benefit Plans - Additional Information (Details) - USD ($) |  | 12 Months Ended | 31 Months Ended |
--- | --- | --- | --- | ---
Jan. 01, 2017 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2019 | Jun. 14, 2017
Employee Benefit Plans |  |  |  |  |  |
Profit sharing contributions |  | $ 0 | $ 0 | $ 0 |  |
Employer contribution to Plan |  | $ 2,500,000 | $ 2,100,000 | 1,500,000 |  |
Common Stock |  |  |  |  |  |
Employee Benefit Plans |  |  |  |  |  |
Stock issued under employee stock purchase plans |  | 26,828 | 8,882 |  | 35,710 |
Employee Stock Purchase Plan |  |  |  |  |  |
Employee Benefit Plans |  |  |  |  |  |
Common stock reserved for sale |  | 164,290 |  |  | 164,290 | 200,000
Compensation expense |  | $ 190,000 | $ 66,000 | $ 0 |  |
3% contributed by employees |  |  |  |  |  |
Employee Benefit Plans |  |  |  |  |  |
Employer matching contribution | 100.00% |  |  |  |  |
Contribution by employees | 3.00% |  |  |  |  |
2% contributed by employees |  |  |  |  |  |
Employee Benefit Plans |  |  |  |  |  |
Employer matching contribution | 50.00% |  |  |  |  |
Contribution by employees | 2.00% |  |  |  |  |

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