UCSB License Agreement - Additional Information (Details) - USD ($) |
3 Months Ended | 6 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Apr. 02, 2019 |
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
Dec. 31, 2018 |
Dec. 31, 2013 |
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| License Agreement [Line Items] | ||||||||||
| Annual minimum royalty obligations | $ 150,000 | $ 150,000 | ||||||||
| License termination period | 60 days | |||||||||
| Common stock, shares issued | 45,403,838 | 45,403,838 | 45,083,209 | |||||||
| Research and development | $ 30,835,000 | $ 25,553,000 | $ 67,211,000 | $ 48,011,000 | ||||||
| Accrued liabilities | 22,469,000 | 22,469,000 | $ 26,724,000 | [1] | ||||||
| AbbVie | Discovery Agreement | Second Target | ||||||||||
| License Agreement [Line Items] | ||||||||||
| Additional sublicense fees | 800,000 | |||||||||
| Milestone payment receivable | 10,000,000.0 | |||||||||
| UCSB | ||||||||||
| License Agreement [Line Items] | ||||||||||
| Common stock, shares issued | 150,000 | 157,332 | ||||||||
| Fair value of common stock price per share | $ 10.68 | |||||||||
| Payment of upfront fees | $ 1,000,000.0 | |||||||||
| Annual license maintenance fees | $ 750,000 | 800,000 | 800,000 | |||||||
| License payment term | 2031 | |||||||||
| Percentage of remaining maintenance fees outstanding | 50.00% | |||||||||
| Fair value of common stock issued | $ 1,600,000 | |||||||||
| Milestone and minimum annual royalty provision paid | 4,400,000 | $ 500,000 | 4,200,000 | $ 500,000 | ||||||
| Accrued liabilities | $ 900,000 | $ 900,000 | $ 3,200,000 | |||||||
| UCSB | Sublicense and Maintenance Fees | ||||||||||
| License Agreement [Line Items] | ||||||||||
| Research and development | $ 3,400,000 | |||||||||
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