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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-option expense	$ 446,113	$ 337,789	$ 1,426,341	$ 823,164
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-option expense	142,254	88,176	444,193	217,766
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-option expense	$ 303,859	$ 249,613	$ 982,148	$ 605,398