Description of the Business and Liquidity (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) item shares	Dec. 31, 2015 USD ($)
Description of Business and Liquidity
Number of dose forms for modulator | item	3
Liquidity
Accumulated deficit	$ (104,402)	$ (97,186)
Common Stock | Secondary public offering
Liquidity
Common stock issued (in shares) | shares	5,056,003
Proceeds from issuance of common stock, net of issuance costs	$ 28,100