Summary of Unvested Restricted Stock Units (Detail) - Restricted Stock Units (RSUs) - shares |
12 Months Ended | |||
|---|---|---|---|---|
Feb. 06, 2017 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
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| Shares | ||||
| Beginning Balance | 358,000 | 84,000 | ||
| Granted | 16,000 | 2,836,000 | 470,000 | 181,000 |
| Vested | (604,000) | (81,000) | (97,000) | |
| Forfeited or cancelled | (427,000) | (115,000) | ||
| Ending Balance | 2,163,000 | 358,000 | 84,000 | |
| X | ||||||||||
- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- 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://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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| X | ||||||||||
- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Details
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