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v3.20.1

Significant Accounting Policies - Additional information (Details) $ in Thousands |  |  |  | 1 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Jan. 01, 2020 shares | Jan. 01, 2019 shares | Jul. 31, 2016 | Jul. 31, 2016 shares | Dec. 31, 2019 USD ($) segment shares | Dec. 31, 2018 USD ($) shares | Dec. 31, 2017 USD ($)
Class of Stock [Line Items] |  |  |  |  |  |  |
Number of operating segments | segment |  |  |  |  | 1 |  |
Number of reportable segments | segment |  |  |  |  | 1 |  |
Certificates of deposit |  |  |  |  | $ 0 | $ 27,600 |
Estimated useful life |  |  |  |  | 5 years |  |
Property, plant and equipment, gross |  |  |  |  | $ 9,826 | 7,490 |
Stock dividend (as a percent) | 2.50% | 2.00% | 2.50% |  |  |  |
Research and development - licenses acquired |  |  |  |  | $ 6,273 | $ 3,360 |
Common stock dividend (in shares) | shares | 1,206,667 | 709,314 |  |  |  |  |
Common Stock, Shares, Issued | shares |  |  |  |  | 39,403,519 | 26,610,183 |
Restricted cash |  |  |  |  | $ 1,000 | $ 500 |
License Agreements [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  | $ 4,900 | $ 2,100 |
License Agreements [Member] | Fortress Biotech, Inc |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Research and development - licenses acquired |  |  |  |  |  |  | $ 9,600
Class A Preferred Shares |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Shares issued for services (in shares) | shares |  |  |  | 250,000 | 0 | 0 |
Stock Issued During Period, Shares, New Issues | shares |  |  |  |  | 0 |  |
Class A Common Shares |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Shares issued for services (in shares) | shares |  |  |  |  | 0 | 0 |
Common Stock, Shares, Issued | shares |  |  |  |  | 845,385 | 1,000,000 |
Stock Issued During Period, Shares, New Issues | shares |  |  |  |  | 0 |  |
Construction in Process |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Property, plant and equipment, gross |  |  |  |  | $ 1,157 | $ 393 |
Cash and Cash Equivalents [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Certificates of deposit |  |  |  |  |  | 10,000 |
Short-term Investments [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Certificates of deposit |  |  |  |  | $ 17,600 | $ 17,600 |

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