Stock-Based Compensation - Schedule of Total Stock-Based Compensation Expense Related to Share-Based Awards Under the Pieris Plan (Detail) - USD ($) |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
|
| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
| Total stock-based compensation expense | $ 649,948 | $ 446,113 | $ 1,962,018 | $ 1,426,341 |
| Research and Development [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
| Total stock-based compensation expense | 216,328 | 142,254 | 573,758 | 444,193 |
| General and Administrative [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
| Total stock-based compensation expense | $ 433,620 | $ 303,859 | $ 1,388,260 | $ 982,148 |