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Fair Value Measurements - Estimated Fair Value of Equity Securities Assumptions (Details) |  | 12 Months Ended |
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Dec. 06, 2017 shares | Dec. 31, 2019 Y $ / shares shares | Mar. 31, 2020 Y $ / shares item
Rezolute |  |  |
Fair Value Measurements |  |  |
Number of tranches | item |  |  | 2
Common Stock Purchase Agreement | Rezolute |  |  |
Fair Value Measurements |  |  |
Number of Rezolute's shares Company has right and option to sell if Rezolute does not list common stock shares on national exchange | shares | 5,000,000 | 5,000,000 |
Closing common stock price | OTC exchange |  |  |
Fair Value Measurements |  |  |
Valuation assumptions, measurement input | $ / shares |  | 0.12 | 0.07
Discount for lack of marketability | Tranche 1 |  |  |
Fair Value Measurements |  |  |
Valuation assumptions, measurement input |  | 0.13 | 0.14
Discount for lack of marketability | Tranche 2 |  |  |
Fair Value Measurements |  |  |
Valuation assumptions, measurement input |  | 0.33 | 35
Estimated time to liquidity of shares | Tranche 1 |  |  |
Fair Value Measurements |  |  |
Valuation assumptions, measurement input |  | 0.25 | 0.25
Estimated time to liquidity of shares | Tranche 2 |  |  |
Fair Value Measurements |  |  |
Valuation assumptions, measurement input |  | 1.5 | 1.5

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