Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) |
3 Months Ended | 6 Months Ended |
|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2018 |
|
| Summary Of Significant Accounting Policies [Line Items] | ||
| Royalty revenue earned | $ 926,477 | $ 1,749,849 |
| Royalty | ||
| Summary Of Significant Accounting Policies [Line Items] | ||
| Royalty revenue earned | $ 0 |