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v3.20.4

Nature of Business, Basis of Presentation and Liquidity Risk - Additional Information (Detail) $ in Thousands |  |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jul. 31, 2020 shares | May 23, 2018 | Dec. 31, 2020 USD ($) shares | Sep. 30, 2020 USD ($) | Jun. 30, 2020 USD ($) | Mar. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) shares | Sep. 30, 2019 USD ($) | Jun. 30, 2019 USD ($) | Mar. 31, 2019 USD ($) | Dec. 31, 2020 USD ($) shares | Dec. 31, 2019 USD ($) shares | Dec. 31, 2018 USD ($)
Accounting Policies [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Accumulated deficit |  |  | $ (60,434) |  |  |  | $ (45,704) |  |  |  | $ (60,434) | $ (45,704) |
Cash and cash equivalents |  |  | 35,853 |  |  |  | 16,664 |  |  |  | 35,853 | 16,664 |
Working capital |  |  | 34,000 |  |  |  |  |  |  |  | 34,000 |  |
Net loss |  |  | $ (4,724) | $ (3,764) | $ (2,922) | $ (3,320) | $ (3,194) | $ (3,673) | $ (3,624) | $ (5,904) | (14,730) | (16,395) | $ (12,687)
Net cash used in operations |  |  |  |  |  |  |  |  |  |  | $ 13,474 | $ 15,216 | $ 10,623
Reverse stock split ratio | 0.05 | 0.1 |  |  |  |  |  |  |  |  |  |  |
Common stock, shares authorized | shares | 150,000,000 |  | 150,000,000 |  |  |  | 150,000,000 |  |  |  | 150,000,000 | 150,000,000 |

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