Cash Proceeds Along with Fair Value Disclosures Related to Grants, Exercises, and Vesting Options (Detail) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | ||||
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Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
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| Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |||||
| Proceeds from stock options exercised | $ 2 | $ 3 | $ 1 | ||
| Intrinsic value of stock options exercised | [1] | $ 1 | |||
| Weighted-average fair value of options granted | $ 1.38 | $ 3.45 | $ 5.15 | ||
| Total fair value of shares vested during the year | $ 1,191 | $ 1,286 | $ 1,728 | ||
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- References No definition available.
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- Definition Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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