Revenues, Recognition and Allowances - Adjustments to Gross Product Sales (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Gross product sales	$ 39,322	$ 48,142	$ 66,736	$ 84,690
Deduction to gross product sales:
Chargebacks and billbacks	11,826	21,449	22,712	38,364
Wholesaler fees for service	2,182	477	3,948	1,112
Sales discounts and other allowances	7,446	11,539	9,713	17,301
Total reduction to gross product sales	21,454	33,465	36,373	56,777
Company product sales, net	18,341	16,249	31,463	30,794
Company product sales
Deduction to gross product sales:
Company product sales, net	$ 17,868	$ 14,677	$ 30,363	$ 27,913