Common Stock - Additional Information 1 (Detail) - USD ($) |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Dec. 31, 2017 |
Mar. 31, 2017 |
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Unrecognized compensation expense related to stock options granted | $ 1,800,000 | $ 2,000,000 | |
| Common shares reserved for awards currently outstanding | 0 | ||
| Stock Options [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Weighted-average period, restricted stock awards | 3 years 2 months 12 days | ||
| Restricted Stock Unit [Member] | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Weighted-average period, restricted stock awards | 3 years 1 month 6 days | ||
| Award vesting period | 4 years | ||
| Stock based compensation expense | $ 37,000 | ||
| Common shares reserved for awards currently outstanding | 205,104 | 210,160 | |
| Total unrecognized compensation expense related to the Company's restricted stock unit awards | $ 500,000 |
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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 Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Unrecognized cost of unvested options awarded to employees as compensation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. 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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