Stockholders' Equity - Restricted Stock (Details) - Unvested restricted stock (Note 6) [Member] - $ / shares |
12 Months Ended | |
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Dec. 31, 2020 |
Dec. 31, 2019 |
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Number of Shares, Nonvested Beginning Balance | 3,303,839 | 2,932,106 |
| Number of Shares, Granted | 1,117,340 | 800,652 |
| Number of Units, Forfeited | 21,000 | |
| Number of Shares, Vested | (551,283) | (407,919) |
| Number of Shares, Nonvested Ending Balance | 3,869,896 | 3,303,839 |
| Weighted Average Exercise Price, Nonvested Beginning Balance | $ 4.29 | $ 4.22 |
| Weighted Average Grant Date Fair Value, Granted | 2.39 | 3.33 |
| Weighted Average Grant Date Fair Value, Forfeited | 3.16 | |
| Weighted Average Grant Date Fair Value, Vested | 5.23 | 1.96 |
| Weighted Average Exercise Price, Nonvested Ending Balance | $ 3.61 | $ 4.29 |
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- 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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- Definition Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- 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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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued 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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- 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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- Definition Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- 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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- Definition The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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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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- Details
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