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Nature of Business and Basis of Presentation - Additional Information (Detail) $ in Thousands |  | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | ---
May 23, 2018 | Jun. 30, 2019 USD ($) | Mar. 31, 2019 USD ($) | Jun. 30, 2018 USD ($) | Mar. 31, 2018 USD ($) | Jun. 30, 2019 USD ($) | Jun. 30, 2018 USD ($) | Dec. 31, 2018 USD ($)
Accounting Policies [Abstract] |  |  |  |  |  |  |  |
Reverse stock split ratio | 0.1 |  |  |  |  |  |  |
Accumulated deficit |  | $ (38,837) |  |  |  | $ (38,837) |  | $ (25,381)
Net loss |  | (3,624) | $ (5,904) | $ (2,788) | $ (3,022) | (9,528) | $ (5,810) |
Cash and cash equivalents |  | 10,446 |  |  |  | 10,446 |  | $ 9,515
Working capital |  | $ 7,800 |  |  |  | $ 7,800 |  |

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