Long-Term Debt - Additional Information - Convertible Notes (Details) - USD ($) |
1 Months Ended | 9 Months Ended | |||||
|---|---|---|---|---|---|---|---|
Aug. 31, 2018 |
Sep. 30, 2019 |
Sep. 30, 2018 |
Jun. 29, 2018 |
Jun. 28, 2018 |
Apr. 02, 2018 |
Feb. 09, 2018 |
|
| Debt Instrument [Line Items] | |||||||
| Outstanding convertible promissory notes and accrued interest converted, amount | $ 0 | $ 14,898,326 | |||||
| Convertible notes outstanding | $ 0 | ||||||
| Convertible Notes | |||||||
| Debt Instrument [Line Items] | |||||||
| Outstanding convertible promissory notes and accrued interest converted, amount | $ 14,900,000 | ||||||
| Convertible Notes | Common Stock | |||||||
| Debt Instrument [Line Items] | |||||||
| Outstanding convertible promissory notes and accrued interest converted, shares | 3,239,294 | ||||||
| Note Purchase Agreement | Convertible Notes | |||||||
| Debt Instrument [Line Items] | |||||||
| Increase the principal amount available for issuance | $ 19,400,000 | $ 18,400,000 | $ 18,400,000 | ||||
| Note Purchase Agreement | Convertible Notes | Maximum | |||||||
| Debt Instrument [Line Items] | |||||||
| Original principal amount | $ 16,000,000 | ||||||