Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accounts Payable and Accrued Expenses [Abstract]
Accrued consulting and clinical trial costs	$ 3,823	$ 2,844
Accrued payroll and related costs	1,847	1,961
Accrued legal and professional fees	3,627	3,605
Other	445	802
Total	$ 9,742	$ 9,212