Commitments and Contingencies - Contract Manufacturing Commitment (Details)			1 Months Ended	12 Months Ended
	Dec. 31, 2015 EUR (€)	Jun. 26, 2014 EUR (€) item shares	May. 31, 2015 EUR (€)	Dec. 31, 2015 EUR (€) item	Mar. 31, 2016 EUR (€)	Jun. 30, 2015 EUR (€)	Mar. 31, 2015 $ / shares	Mar. 25, 2015 EUR (€)	Oct. 30, 2014
Commitments and Contingencies
Exercise price as a percentage of initial public offering price									80.00%
Transfer Agreement | Manufacturer
Commitments and Contingencies
Remaining balance due related to prepayment of technology transfer								€ 310,000
Prepayment of start-up fee	€ 500,000	€ 500,000	€ 500,000	€ 500,000
Prepayment of start-up fee which is to be paid at the earlier to occur of September 15, 2014 or the closing date of an initial public offering		250,000
Prepayment of start-up fee which is to be paid at the time of installation and qualification of the Company's equipment		250,000
Prepayment related to technology transfer		620,000	215,000
Prepayment related to technology transfer which is to be paid within five days of the signature of the Transfer Agreement		310,000
Prepayment related to technology transfer which is to be paid after the delivery of a final study report		310,000
Prepayment for design of a portion of the Manufacturer's facility which is to be paid within five days of the signature of the Transfer Agreement		€ 100,000
Period within which prepayment for design of a portion of the Manufacturer's facility is payable from signature of the Transfer Agreement		5 days
Bonus fee payable	150,000	€ 300,000		150,000
Number of installments | item		2
Bonus fee paid	150,000		€ 150,000	150,000
Aggregate amount payable to Manufacturer upon the delivery of agreed-upon levels of satisfactory product pursuant to the agreement	€ 250,000	€ 500,000		€ 250,000
Number of warrants issued to purchase shares of common stock (in shares) | shares		16,666
Exercise price as a percentage of initial public offering price		90.00%
Exercise price (in dollars per share) | $ / shares							$ 6.30
Increase in prepayment for design of portion of manufacturer facility payable within specified days of signature of agreement								170,000
Transfer Agreement | Manufacturer | Forecast
Commitments and Contingencies
Aggregate amount payable to Manufacturer upon the delivery of agreed-upon levels of satisfactory product pursuant to the agreement					€ 250,000
Transfer Agreement | API
Commitments and Contingencies
Amount of product supplied at no cost (in Kg) | item				400
Amendment to Transfer Agreement first portion due | Manufacturer
Commitments and Contingencies
Prepayment related to technology transfer								€ 215,000
Payments related to design of a portion of manufacturing facility				€ 150,000
Amendment to Transfer Agreement second portion due | Manufacturer
Commitments and Contingencies
Prepayment related to technology transfer						€ 95,000
Payments related to design of a portion of manufacturing facility				€ 20,000