Stockholders' Equity (Deficit) - Summary of Common Stock Reserved for Future Issuance (Detail)
|
Dec. 31, 2021
shares
|
| Class Of Stock [Line Items] |
|
| Common stock issuable upon the exercise of common stock warrants (in shares) |
67,767,107
|
| Total common stock reserved for future issuance (in shares) |
83,721,748
|
| Inducement Plan |
|
| Class Of Stock [Line Items] |
|
| Common stock available for future issuance under the Amended and Restated 2014 Plan (in shares) |
794,737
|
| Common stock available for future issuance under the Amended Inducement Plan (in shares) |
794,737
|
| Options to purchase common stock |
|
| Class Of Stock [Line Items] |
|
| Common stock issuable upon the exercise of stock options outstanding (in shares) |
10,625,062
|
| Options to purchase common stock | 2019 ESPP |
|
| Class Of Stock [Line Items] |
|
| Common stock available for future issuance under 2014 ESPP (in shares) |
1,833,085
|
| Options to purchase common stock | Amended And Restated 2014 Plan |
|
| Class Of Stock [Line Items] |
|
| Common stock available for future issuance under the Amended and Restated 2014 Plan (in shares) |
2,701,757
|
| Common stock available for future issuance under the Amended Inducement Plan (in shares) |
2,701,757
|