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Share-Based Compensation - Summary of non-vested stock option activities (Detail) - $ / shares |  | 9 Months Ended
--- | --- | ---
Jan. 17, 2020 | Sep. 30, 2020
Numbers of shares |  |
Granted |  | 72,000
2017 Plan [Member] |  |
Numbers of shares |  |
Number of shares Outstanding |  | 9,812,881
Vested |  | (8,047,548)
Exercised |  | (115,888)
Forfeited | (332,566) | (336,377)
Surrendered |  | (332,566)
Number of shares Outstanding |  | 980,502
Weighted average Grant date fair value |  |
Weighted average grant date fair value Outstanding |  | $ 2.10
Vested |  | 1.74
Exercised |  | 2.14
Forfeited |  | $ 2.26
Surrendered |  | 1.47
Weighted average grant date fair value Outstanding |  | $ 5.02
2018 Plan [Member] |  |
Numbers of shares |  |
Number of shares Outstanding |  | 3,098,500
Vested |  | (2,273,500)
Number of shares Outstanding |  | 825,000
Weighted average Grant date fair value |  |
Weighted average grant date fair value Outstanding |  | $ 5.57
Vested |  | 5.57
Weighted average grant date fair value Outstanding |  | $ 5.57
2019 Plan [Member] |  |
Numbers of shares |  |
Granted |  | 72,000
Number of shares Outstanding |  | 72,000
Weighted average Grant date fair value |  |
Granted |  | $ 6.09
Weighted average grant date fair value Outstanding |  | $ 6.09
2020 Plan [Member] |  |
Numbers of shares |  |
Granted |  | 1,068,733
Forfeited |  | (18,693)
Number of shares Outstanding |  | 1,050,040
Weighted average Grant date fair value |  |
Forfeited |  | $ 8.65
Granted |  | 8.65
Weighted average grant date fair value Outstanding |  | $ 8.65

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- Definition Share Based Compensation By Share Based Payment Arrangement Non Vested Options Exercises In Period Weighted Average Grant Date Fair Value + References No definition available. + Details
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- Definition Gross number of share options (or share units) granted during the period. + References No definition available. + Details
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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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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