Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Product revenue allowances	$ 12,858	$ 2,856
Selling, general and administrative expenses	5,544	4,812
Research and development expenses	3,379	933
Payroll expenses	7,810	4,199
Contract sales organization expenses	0	4,482
Other	1,788	1,139
Total accrued expenses	31,379	18,421
Lease liability	1,135
Total other current liabilities	1,135
Total accrued expenses and other current liabilities	$ 32,514	$ 18,421