Organization and Description of the Business (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) item $ / shares	Dec. 31, 2014 USD ($)	Jun. 23, 2014
Organization and description of business
Number of clinical-stage product candidates in development | item	2
Working capital	$ 18,300,000
Cash, cash equivalents and investments, Fair Value	$ 20,409,009	$ 53,697,486
Minimum bid price requirement | $ / shares	$ 1.00
Number of days to regain compliance with listing requirements	180 days
Minimum publicly held market value requirement	$ 15,000,000
Minimum total market value requirement	$ 50,000,000
Interest rate (as a percent)	8.00%
Purchase price (as a percent)	100.00%
Debt outstanding	$ 43,750,000
Number of days afforded to regain compliance with minimum publicly held market value of common stock	10 days
Number of days afforded to regain compliance with minimum bid price	10 days
Number of days afforded to regain compliance with minimum market value of common stock	10 days
Revenue	$ 0
8.00% Convertible Senior Notes Due 2019
Organization and description of business
Interest rate (as a percent)	8.00%		8.00%
Debt outstanding	$ 43,750,000