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Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands |  | 1 Months Ended | 12 Months Ended
--- | --- | --- | ---
Apr. 02, 2018 | Jun. 30, 2020 | Dec. 31, 2019 | Feb. 28, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Class of Stock [Line Items] |  |  |  |  |  |  |
Common stock, shares authorized (in shares) |  |  |  |  | 125,000,000 |  |
Common stock, par value (in dollars per share) |  |  |  |  | $ 0.01 |  |
Proceeds from issuance of common stock, net of offering costs |  |  |  |  | $ 170,456 | $ 118,657 | $ 103,259
Undesignated Preferred Stock |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Undesignated preferred stock, shares authorized (in shares) |  |  |  |  | 5,000,000 |  |
Undesignated preferred stock, par value (in dollars per share) |  |  |  |  | $ 0.01 |  |
Undesignated preferred stock, shares issued (in shares) |  |  | 0 |  | 0 | 0 |
Undesignated preferred stock, shares outstanding (in shares) |  |  | 0 |  | 0 | 0 |
Firm Commitment Public Underwritten Offer |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Sale of common stock (in shares) | 4,500,000 |  |  |  |  |  |
Sale of common stock (in dollars per share) | $ 21.25 |  |  |  |  |  |
Proceeds of stock sale | $ 103,300 |  |  |  |  |  |
Over-Allotment Option |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Issuance of common stock, net of offering costs (in shares) |  |  |  | 825,000 |  |  |
Number of shares issued or sold (in shares) |  |  |  | 825,000 |  |  |
Common stock purchase price (in dollars per share) |  |  |  | $ 20.00 |  |  |
Sale of common stock (in shares) | 675,000 |  |  |  |  |  |
Sale of common stock (in dollars per share) | $ 21.25 |  |  |  |  |  |
Follow-On Equity Offering |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Issuance of common stock, net of offering costs (in shares) |  |  |  | 5,500,000 |  |  |
Number of shares issued or sold (in shares) |  |  |  | 5,500,000 |  |  |
Common stock purchase price (in dollars per share) |  |  |  | $ 20.00 |  |  |
Proceeds from issuance of common stock, net of offering costs |  |  |  | $ 118,700 |  |  |
At The Market Offering |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Common stock maximum amount available for issuance |  | $ 175,000 | $ 50,000 |  |  |  |
Sale of common stock (in shares) |  |  |  |  | 6,612,815 |  |
Sale of common stock (in dollars per share) |  |  |  |  | $ 26.46 |  |
Proceeds of stock sale |  |  |  |  | $ 170,500 |  |

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