Stock Based Compensation - Stock-Based Compensation Expense (Detail) - USD ($) |
3 Months Ended | 9 Months Ended | ||
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Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
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| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Amortization of stock-based compensation | $ 1,378,000 | $ 27,000 | $ 1,430,000 | $ 85,000 |
| Research and Development | ||||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Amortization of stock-based compensation | 312,000 | 0 | 312,000 | 0 |
| General and Administrative | ||||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Amortization of stock-based compensation | $ 1,066,000 | $ 27,000 | $ 1,118,000 | $ 85,000 |
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- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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