Capitalization - Class C Preferred Stock (Details) - USD ($)						12 Months Ended
	Apr. 15, 2015	Mar. 17, 2015	Aug. 12, 2014	Aug. 11, 2014	Jun. 20, 2014	Dec. 31, 2015	Dec. 31, 2014
Deerfield Private Design Fund III | Deerfield Convertible Note
Capitalization
Original principal amount converted					$ 500,000
Class C Preferred Stock
Capitalization
Shares issued (in shares)						1,102,945	1,135,084
Class C Preferred Stock | Deerfield Convertible Note
Capitalization
Share issued upon debt conversion (in shares)							126,991
Preferred Stock | Class C Preferred Stock | Deerfield Private Design Fund III and Roche Finance Ltd
Capitalization
Milestone period (in days)			15 days
Written notice period (in days)	5 days
Cash proceeds		$ 5,000,020
Preferred Stock | Class C Preferred Stock | Deerfield Private Design Fund III
Capitalization
Shares issued (in shares)			551,472	504,478
Share price (in dollars per share)			$ 4.53	$ 3.96
Conversion price (in dollars per share)					$ 3.96
Preferred Stock | Class C Preferred Stock | Deerfield Private Design Fund III | Deerfield Convertible Note
Capitalization
Share issued upon debt conversion (in shares)				126,991	126,991
Conversion price (in dollars per share)				$ 3.96
Preferred Stock | Class C Preferred Stock | Roche Finance Ltd
Capitalization
Shares issued (in shares)			551,472	630,606
Share price (in dollars per share)			$ 4.53	$ 3.96