Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accrued expenses:
Selling, general and administrative expenses	$ 5,469	$ 5,544
Research and development expenses	4,468	3,379
Payroll expenses	5,309	7,810
Product revenue allowances	13,386	12,858
Other	1,505	1,788
Total accrued expenses	30,137	31,379
Other current liabilities:
Lease liability	1,256	1,135
Total other current liabilities	1,256	1,135
Total accrued expenses and other current liabilities	$ 31,393	$ 32,514