Redeemable Convertible Preferred Stock - Schedule of Common Stock Reserved for Future Issuance (Details) - shares |
Sep. 30, 2018 |
Sep. 25, 2018 |
|---|---|---|
| Temporary Equity [Line Items] | ||
| Redeemable convertible preferred stock | 16,028,462 | |
| Common stock options issued and outstanding | 3,383,756 | |
| Warrants to purchase redeemable convertible preferred stock | 117,400 | |
| Warrants to purchase common stock | 942 | |
| Total | 22,107,783 | |
| 2018 Equity Incentive Plan | ||
| Temporary Equity [Line Items] | ||
| Remaining shares reserved for issuance under 2018 Equity Incentive Plan | 2,577,223 | |
| Total | 2,300,000 |