Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accrued expenses:
Contract sales organization expenses	$ 808	$ 4,482
Selling, general and administrative expenses	5,115	4,812
Research and development expenses	1,790	933
Payroll expenses	5,392	4,199
Product revenue allowances	6,633	2,856
Other	370	1,139
Total accrued expenses	20,108	18,421
Other current liabilities:
Lease liability	1,448	0
Total other current liabilities	1,448	0
Total accrued expenses and other current liabilities	$ 21,556	$ 18,421