Accrued Expenses (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Accrued Expenses
Accrued manufacturing development costs	$ 7,167,430	$ 513,606
Accrued payroll, bonus and deferred compensation	3,841,171	761,556
Accrued construction in progress	2,978,498
Accrued consulting	1,204,601
Accrued clinical trial costs	388,935	93,621
Accrued professional fees	382,874	348,165
Accrued severance	167,065	153,846
Other	663,429	566,223
Accrued expenses	$ 16,794,003	$ 2,437,017