Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accounts Payable and Accrued Expenses [Abstract]
Accrued consulting and clinical trial costs	$ 3,738	$ 2,844
Accrued payroll and related costs	2,201	1,961
Accrued legal and professional fees	3,574	3,605
Other	2,539	802
Accrued expenses	$ 12,052	$ 9,212