Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Selling, general and administrative expenses	$ 7,268	$ 3,463
Research and development expenses	515	80
Bonus expense	3,120	4,163
Payroll and benefit expenses	757	448
Employee contributions withheld	341	185
Product revenue allowances	2,424	0
Interest expense	308	45
Other	912	314
Accrued Liabilities, Current	$ 15,645	$ 8,698