Stockholders' Equity (Tables)
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12 Months Ended |
Dec. 31, 2018 |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions [Table Text Block] |
The fair value associated with the market award vesting was determined utilizing a binomial valuation methodology and the following assumptions:
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Share-based Compensation, Stock Options, Activity [Table Text Block] |
The following table summarizes stock option activities for the year ended December 31, 2018 and 2017:
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Outstanding at December 31, 2016 |
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Outstanding at December 31, 2017 |
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Outstanding at December 31, 2018 |
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Options vested and exercisable at December 31, 2018 |
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Share-based Compensation, Activity [Table Text Block] |
The following table summarizes stock-based compensation expense for the years ended December 31, 2018 and 2017 (in thousands).
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For the year ended December 31, |
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Total stock-based compensation expense |
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Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] |
A summary of warrant activities for years ended December 31, 2018 and 2017 is presented below:
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Outstanding as of December 31, 2016 |
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Outstanding as of December 31, 2017 |
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Outstanding as of December 31, 2018 |
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Restricted Stock [Member] |
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Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] |
The following table summarizes restricted stock award activities for the year ended December 31, 2018 and 2017:
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Nonvested at December 31, 2016 |
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Nonvested at December 31, 2017 |
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Nonvested at December 31, 2018 |
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Restricted Stock Units (RSUs) [Member] |
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Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] |
The following table summarizes restricted stock units activities for the year ended December 31, 2018 and 2017:
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Nonvested at December 31, 2016 |
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Nonvested at December 31, 2017 |
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Nonvested at December 31, 2018 |
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