Stock Plans - Schedule of Performance-Based Stock Options Activity (Detail) - Performance-based Stock Options [Member] |
3 Months Ended |
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Mar. 31, 2019
$ / shares
shares
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Options, Outstanding, Beginning Balance | shares | 3,167,325 |
| Options Granted | shares | 1,449,102 |
| Options Forfeited | shares | (10,296) |
| Options, Outstanding, Ending Balance | shares | 4,606,131 |
| Weighted-Average Exercise Price, Outstanding, Beginning Balance | $ / shares | $ 21.25 |
| Weighted-Average Exercise Price, Options Granted | $ / shares | 5.67 |
| Weighted-Average Exercise Price, Options Forfeited | $ / shares | 5.65 |
| Weighted-Average Exercise Price, Outstanding, Ending Balance | $ / shares | $ 16.38 |
| Weighted-Average Remaining Contractual Term, Outstanding | 9 years 4 months 6 days |
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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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- Definition The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Gross number of share options (or share units) granted during the period. No definition available.
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- Definition Number of options outstanding, including both vested and non-vested options. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated. No definition available.
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- Definition Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. No definition available.
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- Definition Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Details
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