Equity Incentive Plan - Summary of Stock Option Activity and Related Information (Details) - 2013 Equity Incentive Plan [Member] - $ / shares |
9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2020 |
Dec. 31, 2019 |
|
| Stock Options | ||
| Outstanding at December 31, 2019 (in shares) | 169,980 | |
| Granted (in shares) | 149,191 | |
| Expired (In shares) | (5,021) | |
| Outstanding at September 30, 2020 (in shares) | 314,150 | 169,980 |
| Exercisable at September 30, 2020 (in shares) | 262,203 | |
| Weighted Average Exercise Price | ||
| Outstanding at December 31, 2019 (in dollars per share) | $ 8.13 | |
| Granted (In dollars per share) | 3.40 | |
| Expired (In dollars per share) | 49.39 | |
| Outstanding at September 30, 2020 (in dollars per share) | 5.23 | $ 8.13 |
| Exercisable at September 30, 2020 (in dollars per share) | $ 5.73 | |
| Weighted Average Remaining Life (in years) | ||
| Outstanding (in years) | 8 years 8 months 12 days | 9 years 1 month 6 days |
| Exercisable at September 30, 2020 | 8 years 7 months 6 days |