Summary of Significant Accounting Policies - Going concern (Details) - USD ($) $ in Thousands |
12 Months Ended | |||||
|---|---|---|---|---|---|---|
Feb. 07, 2020 |
Jan. 24, 2020 |
Jan. 13, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
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| Cash and cash equivalents | $ 50,412 | $ 68,379 | ||||
| Marketable securities - available-for-sale debt securities | 39,130 | 136,755 | ||||
| Total stockholders' equity | 123,638 | 246,885 | $ 202,984 | |||
| Net loss | (137,165) | (95,514) | ||||
| Net cash used in operating activities | (112,507) | (104,388) | ||||
| Revenue | $ 1,122 | $ 59,505 | ||||
| Subsequent events. | American Depository Shares (ADSs) | ||||||
| Net proceeds | $ 89,800 | |||||
| Subsequent events. | American Depository Shares (ADSs) | Underwritten Public Offering | ||||||
| Issuance of common stock (in shares) | 21,000,000 | |||||
| Subsequent events. | American Depository Shares (ADSs) | Over-Allotment Option | ||||||
| Issuance of common stock (in shares) | 3,150,000 | |||||
| Subsequent events. | Astellas Pharma Inc. | ||||||
| Upfront payment received | $ 50,000 | |||||
| Research funding | $ 7,500 | |||||
| X | ||||||||||
- Definition Upfront payment received. No definition available.
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| X | ||||||||||
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The amount of compensation earned (contract income) under a research and development arrangement accounted for as a contract to perform research and development for others. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Number of new stock issued during the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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