Organization, Operations and Liquidity (Additional Information) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Product Information [Line Items]
Deficit accumulated during the development stage	$ 296,000
Cash and cash equivalents	26,190	$ 46,620	$ 53,084	$ 75,807
Accounts payable and accrued expenses	$ 2,500