Commitments and Contingencies (Details 2)		1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 26, 2014 EUR (€) item shares	May. 31, 2015 EUR (€)	Sep. 30, 2013 USD ($) item	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2015 EUR (€)	Jun. 30, 2015 EUR (€)	Jun. 30, 2015 USD ($)	Apr. 30, 2015 EUR (€)	Mar. 31, 2015 $ / shares	Mar. 31, 2015 EUR (€)	Mar. 25, 2015 EUR (€)	Aug. 31, 2014 $ / shares
Commitments and Contingencies
Minimum lease payments | $								$ 63,795
Gross aggregate proceeds | $				$ 1,250,000	$ 300,000
Bonus fee payable | $								$ 82,500
Exercise price (in dollars per share) | $ / shares													$ 6.40
Convertible promissory notes
Commitments and Contingencies
Gross aggregate proceeds | $			$ 525,000
Interest rate (as a percent)			8.00%
Number of Convertible Promissory Notes Issued | item			4
Debt Instrument Number of Business Days After Date of Consummation of Initial Closing of First Equity Round of Financing when Debt Instrument Is Due			10 days
Transfer Agreement | Manufacturer
Commitments and Contingencies
Prepayment of start-up fee	€ 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										€ 310,000
Prepayment related to technology transfer which is to be paid within five days of the signature of the Transfer Agreement	310,000						95,000		€ 215,000
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						20,000		150,000
Increase in prepayment for design of portion of manufacturer facility payable within specified days of signature of agreement												170,000
Period within which prepayment for design of a portion of the Manufacturer's facility is payable from signature of the Transfer Agreement	5 days
Prepayment Of StartUp Fee		500,000
Bonus fee payable	€ 300,000											€ 300,000
Bonus fee payable due within specified number of days of signature agreement									€ 150,000
Bonus fee paid		€ 150,000
Number of installments | item	2
Aggregate amount payable to Manufacturer upon the delivery of agreed-upon levels of satisfactory product pursuant to the agreement	€ 500,000						€ 250,000				€ 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
Transfer Agreement | Manufacturer | Scenario, Forecast
Commitments and Contingencies
Bonus fee payable due within specified number of days of signature agreement						€ 150,000