Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Commercial costs	$ 3,514	$ 2,884
Product revenue reserves	17,280	7,620
Royalty payable	2,797	1,735
Research costs	13,049	10,403
Payroll and employee benefits	11,551	12,230
Interest	3,050	3,050
Professional fees	1,439	3,465
Restructuring	255	613
Other current liabilities	95	203
Total accrued expenses and other current liabilities	$ 53,030	$ 42,203