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Net Loss per Share - Additional Information (Detail) - $ / shares | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Nov. 29, 2019 | Apr. 16, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] |  |  |  |  |  |
Weighted average common shares outstanding—basic and diluted (in shares) | 26,609,000 | 20,085,000 | 24,667,000 | 20,035,000 |  |
Pre Funded Warrant |  |  |  |  |  |
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] |  |  |  |  |  |
Exercise Price (usd per share) |  |  |  |  | $ 11.999 | $ 10.999
Pre Funded Warrant | Maximum |  |  |  |  |  |
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] |  |  |  |  |  |
Exercise Price (usd per share) | $ 0.01 |  | $ 0.01 |  |  |
Redeemable Common Stock |  |  |  |  |  |
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] |  |  |  |  |  |
Weighted average common shares outstanding—basic and diluted (in shares) | 229,885 |  |  |  |  |

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