Net and Comprehensive Loss Per Share Attributable to Common Stockholders - Schedule of Weighted Average Common Stock Equivalents Excluded from Calculation of Diluted Net Loss per Share (Detail) - Weighted Average [Member] - shares |
3 Months Ended | |
|---|---|---|
Mar. 31, 2020 |
Mar. 31, 2019 |
|
| Options to Purchase Common Stock [Member] | ||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
| Options to purchase common stock | 4,771,960 | 5,171,960 |
| Warrants to Purchase Common Stock [Member] | ||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
| Options to purchase common stock | 600,000 | 317,562 |