Prepaid Expenses - Prepaid Expenses (Details) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]    
Prepaid developmental expenses $ 1,468,351 $ 2,936,702
Prepaid insurance 734,243 242,980
Other prepaid expenses 315,707 208,201
Total prepaid expenses $ 2,518,301 $ 3,387,883