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Stockholders' Equity - Additional Information (Detail) - USD ($) |  | 1 Months Ended | 3 Months Ended
--- | --- | --- | ---
Jan. 08, 2018 | Jan. 31, 2020 | Mar. 31, 2020
Stockholders Equity Note [Line Items] |  |  |
Net proceeds from public offering |  |  | $ 67,695,000
Common Stock |  |  |
Stockholders Equity Note [Line Items] |  |  |
Common stock, number of shares issued |  |  | 17,867,000
Underwritten Public Offering | Common Stock |  |  |
Stockholders Equity Note [Line Items] |  |  |
Net proceeds from public offering |  | $ 62,700,000 |
Common stock, shares issued and sold |  | 16,866,667 |
Common stock, par value |  | $ 0.001 |
Common stock, sale of stock, price per share |  | $ 3.75 |
Cantor Fitzgerald & Co | Amendment No. 3 | Sales Agreement |  |  |
Stockholders Equity Note [Line Items] |  |  |
Maximum common stock offering price | $ 70,000,000.0 |  |
Percentage of proceeds payable as compensation to underwriter | 2.00% |  |
Unsold shares of common stock, value | $ 31,400,000 |  |
Common stock, number of shares issued |  |  | 1,000,000.0
Net proceeds from public offering |  |  | $ 4,400,000
Common stock registered for sale |  |  | $ 9,600,000

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