Summary of Significant Accounting Policies - Basis of Presentation (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2019 |
Jun. 30, 2019 |
Mar. 31, 2019 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Sep. 30, 2019 |
Sep. 30, 2018 |
Dec. 31, 2018 |
Dec. 31, 2017 |
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| Summary of Significant Accounting Policies | ||||||||||
| Cash and cash equivalents | $ 39,409 | $ 39,409 | $ 68,379 | |||||||
| Marketable securities - available-for-sale debt securities | 63,451 | 63,451 | 136,755 | |||||||
| Total stockholders' equity | 147,683 | $ 186,991 | $ 219,655 | $ 276,155 | $ 165,102 | $ 191,679 | 147,683 | $ 276,155 | $ 246,885 | $ 202,984 |
| Net (loss) income attributable to ordinary shareholders | (39,302) | $ (41,087) | $ (27,412) | 5,242 | $ (43,845) | $ (20,738) | (107,801) | (59,341) | ||
| Net cash used in operating activities | (99,979) | (72,703) | ||||||||
| Revenue | $ 237 | $ 40,792 | $ 394 | $ 58,026 | ||||||
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- References 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 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 Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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