Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Commercial costs	$ 3,179	$ 2,884
Product revenue reserves	18,561	7,620
Royalty payable	2,352	1,735
Research and development costs	9,329	10,403
Payroll and employee benefits	10,275	12,230
Interest	763	3,050
Professional fees	4,516	3,465
Restructuring costs	12	613
Other current liabilities	95	203
Total accrued expenses and other current liabilities	$ 49,082	$ 42,203