Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accrued Expenses
Accrued compensation	$ 9,996	$ 9,145
Accrued professional fees	3,579	6,447
Accrued clinical trial and clinical supply costs	5,241	4,350
Accrued product costs	155	1,794
Accrued interest expense	20	61
Other accrued expenses	4,443	5,630
Total	$ 23,434	$ 27,427